7. x > 6
9. 52 < x < 6
11. − 2 < x < 15
13. n < − 73 or n > 52
15. x < − 4 , 12 < x < 3
17. x < 0 , x > 4
19. − 2 ≤ x ≤ 23
21. x < − 45 , x > 2
23. x < 53
25. 2 ≤ n < 114
27. R < − 12 , R ≥ 8
29. x < − 18 , x > 78
31. x < − 0.68
33. t < 0.69
55. x ≤ 4
57. x ≤ − 3 , x ≥ 0
59. Max P = 29 at (1, 3)
61. Min C = 658at (38 , 74)
63. a and b must have different signs.
65. x < − 3 or x > 2
67. x2 − 2x − 15 < 0
f(x) > 0 for x < 2 or x > 3f(x) < 0 for 2 < x < 3f(x) = 0 for x = 2 , x = 3f(0) = 6 , f(5) = 6
73. No values satisfy both inequalities
75. 0 < x ≤ 8.0 cm
77. Between $5 and $12.50
79. d > 39.5 m
81. 168,000 ≤ B ≤ 400,000 Btu
83. 0.456 < i < 0.816 A
85. r > 5.7
89. 300 regular
150 deluxe
(Max P = $4650)
18.222.111.24