Solve each problem.
7.The 2009 Indianapolis 500 (mile) race was won by Helio Castroneves, who averaged
150.318 mph. What was his time to the nearest thousandth of an hour? (Source: World
Almanac and Book of Facts.)
8.A certificate of deposit pays $2281.25 in simple interest for 1 yr on a principal of
$36,500. What is the rate of interest?
9.In 2008, there were 36,723 offices, stations, and branches of the U.S. Postal Service, of
which 27,232 were actually classified as post offices. What percent, to the nearest tenth,
were classified as post offices? (Source:U.S. Postal Service.)
10.Tyler McGinnis invested some money at 3% simple interest and some at 5% simple inter-
est. The total amount of his investments was $28,000, and the interest he earned during
the first year was $1240. How much did he invest at each rate?
11.Two cars leave from the same point at the same time, traveling in opposite directions. One
travels 15 mph slower than the other. After 6 hr, they are 630 mi apart. Find the rate of
each car.
12.Find the measure of each angle.
132 CHAPTER 2 Linear Equations, Inequalities, and Applications
(2x + 20)°
x° x°
Solve each inequality. Give the solution set in both interval and graph forms.
15. 16.
17.Concept Check Which one of the following inequalities is equivalent to
A. B. C. D.
18.A student must have an average of at least 80 on the four tests in a course to get a B. The
student had scores of 83, 76, and 79 on the first three tests. What minimum score on the
fourth test would guarantee the student a B in the course?
19.Let and Write each of the following sets.
(a) (b)
Solve each compound or absolute value inequality.
- and 21. or
Solve each absolute value equation.
28.Concept Check If what is the solution set of each of the following?
(a)| 8 x- 5 | 6 k (b)| 8 x- 5 | 7 k (c)| 8 x- 5 |=k
k 6 0,
| 3 x- 2 |+ 1 = 8 | 3 - 5 x|=| 2 x+ 8 |
| 7 - x|...- 1 |- 3 x+ 4 |- 4 6- 1
| 4 x+ 3 |... 7 | 5 - 6 x| 712
3 xÚ 6 x- 465 - 4 x...- 24 4 x- 2610
A ̈B A ́B
A= 5 1, 2, 5, 7 6 B= 5 1, 5, 9, 12 6.
- 3 x 69 - 3 x7- 9 - 3 x 79 - 3 x6- 9
x6-3?
- 6 ...
4
3
-
4
7
4 - 61 x+ 32 ...- 2 - 31 x+ 62 + 3 x x7- 16
