Solutions

Solutions to Try Its

1. m=4−30−2=1−2=−12m=4−30−2=1−2=−12 ; decreasing because m<0m<0. 2. m=1,868−1,4422,012−2,009=4263=142 people per yearm=1,868−1,4422,012−2,009=4263=142 people per year 3. y−2=−2(x+2)y−2=−2(x+2); y=−2x−2y=−2x−2 4. y−0=−3(x−0)y−0=−3(x−0) ; y=−3xy=−3x 5. y=−7x+3y=−7x+3 6. H(x)=0.5x+12.5H(x)=0.5x+12.5

Solutions to Odd-Numbered Exercises

1. Terry starts at an elevation of 3000 feet and descends 70 feet per second.

3. 3 miles per hour

5. d(t)=100−10td(t)=100−10t

7. Yes.

9. No.

11. No.

13. No.

15. Increasing.

17. Decreasing.

19. Decreasing.

21. Increasing.

23. Decreasing.

25. 3

27. −13−13

29. 4545

31. f(x)=−12x+72f(x)=−12x+72

33. y=2x+3y=2x+3

35. y=−13x+223y=−13x+223

37. y=45x+4y=45x+4

39. −54−54

41. y=23x+1y=23x+1

43. y=−2x+3y=−2x+3

45. y=3y=3

47. Linear, g(x)=−3x+5g(x)=−3x+5

49. Linear, f(x)=5x−5f(x)=5x−5

51. Linear, g(x)=−252x+6

53. Linear, f(x)=10x−24

55. f(x)=−58x+17.3

57.

59. a. a=11,900 ; b=1001.1 b. q(p)=1000p−100

61.
..

63. x=−163

65. x=a

67. y=dc−ax−adc−a

69. $45 per training session.

71. The rate of change is 0.1. For every additional minute talked, the monthly charge increases by $0.1 or 10 cents. The initial value is 24. When there are no minutes talked, initially the charge is $24.

73. The slope is –400. This means for every year between 1960 and 1989, the population dropped by 400 per year in the city.

75. c