Solutions to Selected Exercises

Solutions to Try Its

1. 11 and 25

2. [latex]C=2.5x+3,650[/latex]

3. 45 mi/h

4. [latex]L=37[/latex] cm, [latex]W=18[/latex] cm

5. 250 ft2

Solutions to Odd-Numbered Exercises

1. Answers may vary. Possible answers: We should define in words what our variable is representing. We should declare the variable. A heading.

3. [latex]2,000-x[/latex]

5. [latex]v+10[/latex]

7. Ann: [latex]23[/latex]; Beth: [latex]46[/latex]

9. [latex]20+0.05m[/latex]

11. 300 min

13. [latex]90+40P[/latex]

15. 6 devices

17. [latex]50,000-x[/latex]

19. 4 h

21. She traveled for 2 h at 20 mi/h, or 40 miles.

23. $5,000 at 8% and $15,000 at 12%

25. [latex]B=100+.05x[/latex]

27. Plan A

29. [latex]R=9[/latex]

31. [latex]r=\frac{4}{5}[/latex] or 0.8

33. [latex]W=\frac{P - 2L}{2}=\frac{58 - 2\left(15\right)}{2}=14[/latex]

35. [latex]f=\frac{pq}{p+q}=\frac{8\left(13\right)}{8+13}=\frac{104}{21}[/latex]

37. [latex]m=\frac{-5}{4}[/latex]

39. [latex]h=\frac{2A}{{b}_{1}+{b}_{2}}[/latex]

41. length = 360 ft; width = 160 ft

43. 405 mi

45. [latex]A=88\text{ in}{.}^{2}[/latex]

47. 28.7

49. [latex]h=\frac{V}{\pi {r}^{2}}[/latex]

51. [latex]r=\sqrt{\frac{V}{\pi h}}[/latex]

53. [latex]C=12\pi [/latex]