Determine whether each expression is a monomial. Write yes ..., Exercises of Reasoning

Download Determine whether each expression is a monomial. Write yes ... and more Exercises Reasoning in PDF only on Docsity! Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 1 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 2 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 5 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 6 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 7 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 10 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 11 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 12 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 15 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 16 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 17 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 20 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 21 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 22 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 25 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 26 7-1 Multiplication Properties of Exponents Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 1. 15 SOLUTION:   15 is a monomial. It is a constant and all constants are monomials. 2. 2− 3a SOLUTION:   2− 3a is not a monomial. There is subtraction and more than one term. 3.  SOLUTION:   is not a monomial. There is a variable in the denominator. 4. −15g 2 SOLUTION:   −15g 2 is a monomial. It is the product of a number and variables. 5.  SOLUTION:   is a monomial. It is the product of a number and a variable. 6. 7b + 9 SOLUTION:   No; there is addition and more than one term. Simplify each expression. 7. k(k 3 ) SOLUTION:   8. m4 (m 2 ) SOLUTION:   9. 2q 2 (9q 4 ) SOLUTION:   10. (5u 4 v)(7u 4 v 3 ) SOLUTION:   11. [(3 2 ) 2 ] 2 SOLUTION:   12. (xy 4 ) 6 SOLUTION:   13. (4a 4 b 9 c) 2 SOLUTION:   14. (−2f 2 g 3 h 2 ) 3 SOLUTION:   15. (−3p 5 t 6 ) 4 SOLUTION:   16. GEOMETRY  The formula for the surface area of a cube is SA = 6s 2 , where SA is the surface area and s is the length of any side. a.  Express the surface area of the cube as a monomial. b.  What is the surface area of the cube if a = 3 and b = 4? SOLUTION:   a.   b.   So the surface area is 69,984 square units. Simplify each expression. 17. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   18. (−3d 2 f 3 g) 2 [(−3d 2 f ) 3 ] 2 SOLUTION:   19. (−2g 3 h)(−3gj 4 ) 2 (−ghj) 2 SOLUTION:   20. (−7ab 4 c) 3 [(2a 2 c) 2 ] 3 SOLUTION:   Determine whether each expression is a monomial. Write yes or no. Explain your reasoning. 21. 122 SOLUTION:   122 is a monomial. A constant is a monomial. 22. 3a 4 SOLUTION:   3a 4 is a monomial. It is the product of a number and variables.  23. 2c + 2 SOLUTION:   2c + 2 is not a monomial. It involves addition and has more than one term. 24.  SOLUTION:   is not a monomial. The expression has a variable in the denominator. 25.  SOLUTION:   is a monomial. It can be written as the product of a number and variable. 26. 6m + 3n SOLUTION:   6m + 3n is not a monomial. In the expression, there is addition and more than one term. Simplify each expression. 27. (q 2 )(2q 4 ) SOLUTION:   28. (−2u 2 )(6u 6 ) SOLUTION:   29. (9w 2 x 8 )(w 6 x 4 ) SOLUTION:   30. (y6 z 9 )(6y 4 z 2 ) SOLUTION:   31. (b 8 c 6 d 5 )(7b 6 c 2 d) SOLUTION:   32. (14fg 2 h 2 )(−3f 4 g 2 h 2 ) SOLUTION:   33. (j 5 k 7 ) 4 SOLUTION:   34. (n3 p ) 4 SOLUTION:   35. [(2 2 ) 2 ] 2 SOLUTION:   36. [(32 ) 2 ] 4 SOLUTION:   37. [(4r 2 t) 3 ] 2 SOLUTION:   38. [(−2xy 2 ) 3 ] 2 SOLUTION:   GEOMETRY  Express the area of each triangle as a monomial. 39.  SOLUTION:   40.  SOLUTION:   Simplify each expression. 41. (2a 3 ) 4 (a 3 ) 3 SOLUTION:   42. (c3 ) 2 (−3c 5 ) 2 SOLUTION:   43. (2gh 4 ) 3 [(−2g 4 h) 3 ] 2 SOLUTION:   44. (5k 2 m) 3 [(4km 4 ) 2 ] 2 SOLUTION:   45. (p 5 r 2 ) 4 (−7p 3 r 4 ) 2 (6pr 3 ) SOLUTION:   46. (5x 2 y) 2 (2xy 3 z) 3 (4xyz) SOLUTION:   47. (5a 2 b 3 c 4 )(6a 3 b 4 c 2 ) SOLUTION:   48. (10xy 5 z 3 )(3x 4 y 6 z 3 ) SOLUTION:   49. (0.5x 3 ) 2 SOLUTION:   50. (0.4h 5 ) 3 SOLUTION:   51.  SOLUTION:   52.  SOLUTION:   53. (8y 3 )(−3x 2 y 2 ) SOLUTION:   54.  (49m)(17p ) SOLUTION:   55. (−3r 3 w 4 ) 3 (2rw) 2 (−3r 2 ) 3 (4rw 2 ) 3 (2r 2 w 3 ) 4 SOLUTION:   56. (3ab 2 c) 2 (−2a 2 b 4 ) 2 (a 4 c 2 ) 3 (a 2 b 4 c 5 ) 2 (2a 3 b 2 c 4 ) 3 SOLUTION:   57. FINANCIAL LITERACY  Cleavon has money in an account that earns 3% simple interest. The formula for computing simple interest is I = Prt, where I is the interest earned, P represents the principal that he put into the account, r is the interest rate (in decimal form), and t represents time in years. a.  Cleavon makes a deposit of $2c and leaves it for 2 years. Write a monomial that represents the interest earned. b.  If c represents a birthday gift of $250, how much will Cleavon have in this account after 2 years? SOLUTION:   a. b. Cleavon will make $30 interest, so he will have 250 + 30 = $280 in his account. CCSS TOOLS  Express the volume of each solid as a monomial. 58.  SOLUTION:   59.  SOLUTION:   60.  SOLUTION:   61. PACKAGING  For a commercial art class, Aiko must design a new container for individually wrapped pieces of candy. The shape that she chose is a cylinder. The formula for the volume of a cylinder is V = πr 2 h. a.  The radius that Aiko would like to use is 2p 3 , and the height is 4p 3 . Write a monomial that represents the volume of her container. b.  Make a table of five possible measures for the radius and height of a cylinder having the same volume. c.  What is the volume of Aiko’s container if the height is doubled? SOLUTION:   a. b. The product of the square of the radius’ coefficient and the height’s coefficient must be 16. The exponents of the radius and the height must have a sum of 9. Sample answer: c. If the height is doubled, h = 2(4p 3 ) = 8p 3 So, the volume of Aiko’s container is 32πp 9 cubic units. 62. ENERGY  Albert Einstein’s formula E = mc 2 shows that if mass is accelerated enough, it can be converted into usable energy. Energy E is measured in joules, mass m in kilograms, and the speed of light is about 300 million meters per second.   a.  Complete the calculations to convert 3 kilograms of gasoline completely into energy. b.  What is the energy if the amount of gasoline is doubled? SOLUTION:   a. So, 3 kilograms of gasoline converts to 270,000,000,000,000,000 joules of energy. b. If the amount of gasoline is doubled to 6 kilograms, then the energy is also doubled. 63. MULTIPLE REPRESENTATIONS  In this problem, you will explore exponents. a.  TABULAR  Copy and use a calculator to complete the table. b.  ANALYTICAL  What do you think the values of 5 0 and 5 −1 are? Verify your conjecture using a calculator. c.  ANALYTICAL  Complete: For any nonzero number a and any integer n, a −n = ______. d.  VERBAL  Describe the value of a nonzero number raised to the zero power. SOLUTION:   a. b. If 30 = 1, then 5 0 may also equal 1. If 3 -1 equals one-third, then 5 -1 may equal one-fifth. c. From the table, it seems that a number raised to a negative power is the same the same as its reciprocal raised to the same power, only positive. So, d. Any nonzero number raised to the zero power is 1. 64. CCSS PERSEVERANCE  For any nonzero real numbers a and b and any integers m and t, simplify the expression  and describe each step. SOLUTION:     Move the negative sign to the numerator. Since raising the fraction to the 2t power means multiplying both the numerator and the denominator by themselves 2t times, we can rewrite the expression as the power of a power for both the numerator and the denominator.    To find the power of the power, multiply the exponents.   Regroup the numerator to isolate the negative base.    Simplify the numerator and denominator.   Use the power of a power rule one last time to simplify.       65. REASONING  Copy the table below. a.  For each equation, write the related expression and record the power of x. b.  Graph each equation using a graphing calculator. c.  Classify each graph as linear or nonlinear. d.  Explain how to determine whether an equation, or its related expression, is linear or nonlinear without graphing. SOLUTION:   a. b. c. d. If the power of x is 1, the equation or its related expression is linear. 66. OPEN ENDED  Write three different expressions that can be simplified to x 6 . SOLUTION:       Sample answer: x 4 ⋅ x2 ; x 5 ⋅ x; For these, the exponents must have a sum of 6.     (x 3 ) 2 ; For this type, the product of 3 and 2 is 6. 67. WRITING IN MATH  Write two formulas that have monomial expressions in them. Explain how each is used in a real-world situation. SOLUTION:   Sample answer: The area of a circle or A = πr 2 , where r is the radius, can be used to find the area of any circle. The area of a rectangle or A = w ⋅ ℓ, where w is the width and ℓ is the length, can be used to find the area of any rectangle. 68. Which of the following is not a monomial? A  −6xy B   C   D  5gh 4 SOLUTION:   The only example that has a negative exponent is C. This means that the term has a variable in the denominator. Therefore it is not a monomial and choice C is the correct answer. 69. GEOMETRY  The accompanying diagram shows the transformation of ΔXYZ to ΔX′Y′Z′. This transformation is an example of a F  dilation G  line reflection H  rotation J  translation SOLUTION:   Because the original triangle got smaller in the transformation, it is a dilation. None of the other types of transformations involve changing the size of a shape (they only affect location). Therefore, choice F is the correct answer. 70. CARS In 2002, the average price of a new domestic car was $19,126. In 2008, the average price was $28,715. Based on a linear model, what is the predicted average price for 2014? A $45,495 B $38,304  C $35,906 D $26,317 SOLUTION:   Let x be the year and let y be the average price of a new domestic car. Since all the points are part of a linear model, the slope between any two points will be the same.Find the slope of the line containing the data points (2002, 19,126) and (2008, 28,715) .     Use this slope and the points (2002, 19,126) and (2014, y 2) to determine the average cost of a new domestic car in 2014.       The predicted average price of a new domestic car for 2014 is about $38,304.  Therefore, the correct choice is B. 71. SHORT RESPONSE  If a line has a positive slope and a negative y–intercept, what happens to the x–intercept if the slope and the y–intercept are doubled? SOLUTION:   The y–intercept of the graphed equation is –4 and the slope is 2, so the equation would be . From the graph, we see that the x–intercept is 2. Now, double the slope and intercept, and the new equation is . Substitute y = 0, to find the x–intercept. Notice that the x–intercept does not change. Solve each system of inequalities by graphing. 72. y < 4x 2x + 3y  ≥ −21 SOLUTION:   Write equation 2 in slope, intercept form.      Graph each inequality. The graph of y < 4x is dashed and is not included in the graph of the solution. The graph of 2x + 3y ≥ −21 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y < 4x and 2x + 3y ≥ −21. This region is darkly shaded in the graph below. 73. y ≥ 2 2y + 2x ≤ 4 SOLUTION:   Write equation 2 in slope-intercept form.   Graph each inequality. The graph of y  ≥ 2 is solid and is not included in the graph of the solution. The graph of 2y + 2x ≤ 4 is also solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y  ≥ 2 and 2y + 2x ≤ 4. This region is darkly shaded in the graph below. 74. y > −2x − 1 2y  ≤ 3x + 2 SOLUTION:   Rewrite equation 2 in slope-intercept form. Graph each inequality. The graph of y > −2x − 1 is dashed and is not included in the graph of the solution. The graph of 2y  ≤ 3x + 2 is solid and is included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of y > −2x − 1 and 2y  ≤ 3x + 2. This region is darkly shaded in the graph below. 75. 3x + 2y < 10 2x + 12y < –6 SOLUTION:   Write each equation in slope-intercept form. Equation 1:  Equation 2:    Graph each inequality. The graph of 3x + 2y < 10 is dashed and is not included in the graph of the solution. The graph of 2x + 12y < –6 is also dashed and is not included in the graph of the solution. The solution of the system is the set of ordered pairs in the intersection of the graphs of 3x + 2y < 10 and 2x + 12y < –6. This region is darkly shaded in the graph below. 76. SPORTS In the 2006 Winter Olympic Games, the total number of gold and silver medals won by the U.S. was 18. The total points scored for gold and silver medals was 45. Write and solve a system of equations to find how many gold and silver medals were won by the U.S.   SOLUTION:   Each gold medal is worth 3 points and each silver medal is worth 2 points. So, if the U.S. won g gold medals and s silver medals, then they won 3g + 2s points.   The total number of gold and silver medals, g + s, is 18. So, we have 2 equations:   Solve the 2nd equation for g.     Substitute for g in the other equation.     g = 18 – 9 = 9   g = 9; s = 9 77. DRIVING Tires should be kept within 2 pounds per square inch (psi) of the manufacturer’s recommended tire pressure. If the recommendation for a tire is 30 psi, what is the range of acceptable pressures? SOLUTION:   30 + 2 = 32 30 - 2 = 28   The pressure will range between 28 and 32 psi, inclusive. 78. BABYSITTING  Alexis charges $10 plus $4 per hour to babysit. Alexis needs at least $40 more to buy a television for which she is saving. Write an inequality for this situation. Will she be able to get her television if she babysits for 5 hours? SOLUTION:   Let h represent the number of hours that Alexis has to babysit. If she babysits 5 hours, substitute h = 5 into the inequality. This inequality is not true, so she will not be able to afford her television if she babysits for 5 hours. Find each quotient. 79. −64 ÷ (−8) SOLUTION:   The quotient of two negative integers is positive. −64 ÷ (−8) = 8 80. −78 ÷ 1.3 SOLUTION:   The quotient of a negative number and a positive number is negative. −78 ÷ 1.3 = –60 81. 42.3 ÷ (−6) SOLUTION:   The quotient of a positive number and a negative number is negative. 42.3 ÷ (−6) = –7.05 82. −23.94 ÷ 10.5 SOLUTION:   The quotient of a negative number and a positive number is negative. −23.94 ÷ 10.5 = –2.28 83. −32.5 ÷ (−2.5) SOLUTION:   The quotient of two negative numbers is positive. −32.5 ÷ (−2.5) = 13 84. −98.44 ÷ 4.6 SOLUTION:   The quotient of a negative number and a positive number is negative. −98.44 ÷ 4.6 = –21.4 eSolutions Manual - Powered by Cognero Page 27 7-1 Multiplication Properties of Exponents