## Solutions to Try Its

1. $m=\frac{4 - 3}{0 - 2}=\frac{1}{-2}=-\frac{1}{2}$ ; decreasing because $m<0$.

2. $m=\frac{1,868 - 1,442}{2,012 - 2,009}=\frac{426}{3}=142\text{ people per year}$

3. $y - 2=-2\left(x+2\right)$; $y=-2x - 2$

4. $y - 0=-3\left(x - 0\right)$ ; $y=-3x$

5. $y=-7x+3$

6. $H\left(x\right)=0.5x+12.5$

## 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. $d\left(t\right)=100 - 10t$

7. Yes.

9. No.

11. No.

13. No.

15. Increasing.

17. Decreasing.

19. Decreasing.

21. Increasing.

23. Decreasing.

25. 3

27. $-\frac{1}{3}$

29. $\frac{4}{5}$

31. $f\left(x\right)=-\frac{1}{2}x+\frac{7}{2}$

33. $y=2x+3$

35. $y=-\frac{1}{3}x+\frac{22}{3}$

37. $y=\frac{4}{5}x+4$

39. $-\frac{5}{4}$

41. $y=\frac{2}{3}x+1$

43. $y=-2x+3$

45. $y=3$

47. Linear, $g\left(x\right)=-3x+5$

49. Linear, $f\left(x\right)=5x - 5$

51. Linear, $g\left(x\right)=-\frac{25}{2}x+6$

53. Linear, $f\left(x\right)=10x - 24$

55. $f\left(x\right)=-58x+17.3$

57.

59. a. $a=11,900$ ; $b=1001.1$ b. $q\left(p\right)=1000p - 100$

61.

63. $x=-\frac{16}{3}$

65. $x=a$

67. $y=\frac{d}{c-a}x-\frac{ad}{c-a}$

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