Page 784 - Basic College Mathematics with Early Integers

A16 ANSWERS TO SELECTED EXERCISES

Section 8.4

Calculator Explorations 1. yes 3. no 5. yes
Vocabulary and Readiness Check 1. 3x - 9 + x - 16; 5(2x + 6) - 1 = 39 3. addition 5. distributive
Answers to Selected Exercises
Exercise Set 8.4 1. 3 3. 1.9 5. -4 7. 100 9. -3.9 11. -4 13. -12 15. -3 17. -1 19. -45 21. -9 23. 6 25. -5 27. 5
29. 8 31. 0 33. -22 35. 6 37. -11 39. -7 41. -5 43. 5 45. -3 47. 2 49. -4 51. -1 53. 4 55. 3 57. -1 59. 8 61. 4
1 3 9
63. 3 65. 64 67. 69. 71. -54 73. 2 75. 77. 270 79. 0 81. 4 83. 1 85. -42 + 16 =-26 87. -51-292 = 145
9 2 5
100
89. 31-14 - 22 =-48 91. = 1 93. 97 or 98 million returns 95. 9 million returns 97. b 99. a 101. 6x - 10 = 5x - 7
21502
6x = 5x + 3
103. 0 105. -4 107. no; answers may vary 109. 123.26°F 111. -9.4°F x = 3
Section 8.5
x
Exercise Set 8.5 1. x + 5 3. x + 8 5. 20 - x 7. 512x 9. 11. 17 + x + 5x 13. -5 + x =-7 15. 3x = 27 17. -20 - x = 104
2
10
19. 5x 21. 11 - x 23. 2x = 108 25. 50 - 8x 27. 51-3 + x2 =-20 29. 9 + 3x = 33; 8 31. 3 + 4 + x = 16; 9 33. x - 3 = 5 ;
5
108
35. 30 - x = 31x + 62; 3 37. 5x - 40 = x + 8; 12 39. 31x - 52 = ; 8 41. 4x = 30 - 2x; 5 43. California: 55 votes; Florida: 27 votes
12
45. falcon: 185 mph; pheasant: 37 mph 47. Pakistan: 1806 thousand students; India: 1500 thousand students 49. Xbox: $420; games: $140 51. 5470 miles
53. Michigan Stadium: 106,201; Beaver Stadium: 107,282 55. China: 140 million; Spain: 70 million 57. 27 points 59. 2010: 275,215; 2020: 808,416
61. Spain: 6609 cars per day; Germany: 13,218 cars per day 63. $225 65. USA: 240,500 million; Japan: 77,950 million 67. 590 69. 1000
71. 3000 73. yes; answers may vary 75. $216,200 77. $549
Chapter 8 Vocabulary Check 1. simplified; combined 2. like 3. variable 4. algebraic expression 5. terms 6. numerical coefficient
7. evaluating the expression 8. constant 9. equation 10. solution 11. distributive 12. multiplication 13. addition
7
Chapter 8 Review 1. -5 2. 17 3. undefined 4. 0 5. 129 6. -2 7. 8 cu ft 8. 64 cu ft 9. $1800 10. $300 11. -15x 12. - x
30
13. -6y - 10 14. -6a - 7 15. -8y + 2 16. 4.6x - 11.9 17. -8y 18. 15y - 24 19. 11x - 12 20. 4x - 7 21. -5a + 4 22. 12y - 9
1 6
2
23. 16x - 32 sq yd 24. 9y sq m 25. yes 26. no 27. -2 28. 7 29. - 30. - 31. -6 32. -20 33. 1.3 34. 2.4 35. 7 36. -9
2 11
4
37. 1 38. -5 39. - 40. -24 41. -120 42. 13 43. 4 44. 3 45. 5 46. 12 47. 63 48. 33 49. -2.25 50. 1.3 51. 2 52. 6 53. 11
5
-75 70
54. -5 55. 6 56. 8 57. 20 - 1-82 = 28 58. -2 - 19 =-21 59. =-3 60. -51-2 + 62 =-20 61. 62. x - 13 63. 85 - x
5 + 20 x
64. 2x + 11 65. x + 8 = 40 66. 2x - 12 = 10 67. 5 68. -16 69. bamboos: 36 inches; kelp: 18 inches 70. incumbent: 14,752 votes;
1 x
challenger: 3546 votes 71. 29 72. - 73. -11x 74. -35x 75. 22x - 19 76. -9x - 32 77. x - 17 78. 31x + 52 79. x - 3 =
4 4
3 8
80. 6x = x + 2 81. no 82. yes 83. -1 84. -25 85. 13 86. -6 87. 17 88. 7 89. -22 90. -6 91. - 92. -4 93. 2 94. -
4 3
95. 12 96. -8 97. 0 98. 0 99. 5 100. 1
1
Chapter 8 Test 1. -1 2. -5x + 5 3. -6y - 14 4. 14z - 8 5. 4(3x - 1); 112x - 42 sq m 6. 7 7. - 8. -12 9. 40 10. 24 11. 3
2
22
12. -2 13. -2 14. 4.5 15. 0 16. -2 17. 18. 4 19. 0 20. 6000 sq ft 21. 30 sq ft 22. a. 17x b. 20 - 2x 23. -2 24. 34 points
3
25. 244 women
Cumulative Review 1. hundred-thousands; Sec. 1.2, Ex. 1 2. two thousand thirty-six; Sec. 1.2 3. 184,046; Sec. 1.3, Ex. 2 4. 39; Sec. 1.7
5. 13 in.; Sec. 1.3, Ex. 5 6. 17; Sec. 1.4 7. 98,638; Sec. 1.3, Ex. 7 8. 5; Sec. 1.9 9. 7321; Sec. 1.4, Ex. 2 10. 64; Sec. 1.9 11. a. Indonesia
1
b. 236; Sec. 1.3, Ex. 8 12. - ; Sec. 3.3 13. 4; Sec. 2.2, Ex. 6a 14. -20 ; Sec. 2.2 15. -5 ; Sec. 2.2, Ex. 6b 16. 0; Sec. 2.2 17. -23 ; Sec. 2.3, Ex. 4
8
1 31
18. -3.6 ; Sec. 4.2 19. -10 ; Sec. 2.3, Ex. 14 20. ; Sec. 3.5 21. -7 ; Sec. 2.4, Ex. 6 22. 5.8; Sec. 4.2 23. 1; Sec. 2.4, Ex. 7 24. - ; Sec. 3.5
10 120
25. 10; Sec. 2.5, Ex. 2 26. -9.6 ; Sec. 4.3 27. 24; Sec. 2.5, Ex. 7 28. -4 ; Sec. 3.7 29. 3; Sec. 2.6, Ex. 9 30. 9.7; Sec. 8.2 31. 0.8496; Sec. 4.3, Ex. 2
5 7 23 7
32. 53.1; Sec. 4.3 33. a. b. ; Sec. 5.1, Ex. 6 34. ; Sec. 3.5 35. 5; Sec. 6.2, Ex. 9 36. ; Sec. 3.3 37. 75%; Sec. 6.2, Ex. 11
7 24 36 12
18
38. ; Sec. 3.7 39. 48 oz; Sec. 5.5, Ex. 2 40. 24,000; Sec. 1.5 41. 11.3 L or 11,300 mL; Sec. 5.6, Ex. 8 42. 0.024; Sec. 4.1 43. yes; Sec. 5.2, Ex. 4
23
1
44. yes; Sec. 5.2 45. 22.4 cc; Sec. 5.3, Ex. 2 46. 262.5 mi; Sec. 5.3 47. 0.046; Sec. 6.1, Ex. 4 48. 4.52; Sec. 6.1 49. ; Sec. 6.1, Ex. 11
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27 5 p
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50. ; Sec. 6.1 51. 5 = n 20; Sec. 6.2, Ex. 1 52. = ; Sec. 6.3 53. sales tax: $6.41; total price: $91.91; Sec. 6.5, Ex. 1 54. $1610; Sec. 6.5
100 20 100
55. a. 62 clam species b. birds and fishes; Sec. 7.1, Ex. 3 56. mean: 8; median: 9; mode: 11; Sec. 7.3