Page 171 - Math Course 1 (Book 1)

Inequalities: Multiplication and Division

Read the Test Item Your Turn!
You are to write an inequality to represent a
real-world problem. Multiply or Divide by a Positive Number

Solve the Test Item Solve 3y > 21. Check your solution.
Words Amount earned per hour times A. y > 63
number of hours is at least amount B. y > 7
earned each week. C. y < 18
Variables Let x represent the number of hours D. y < 7
worked.
Answer
Inequality 9 • x ≥ 117

p
Answer The answer is B. Solve 6 < Check your solution.
3

Multiply or Divide by a Negative A. p ≥ 2
Number B. p ≥ 3
C. p ≥ 18
D. p ≤ 18
Examples
Answer
x
Solve > 7 and check your solution. Then
-5
graph the solution on a number line.

x > 7 Write the inequality. Standardized Test Example
-5
x
-5 ( ( < -5 (7) Multiply each side by –5 and Ed earns $6 per hour working at the
library. Which inequality can be used
-5
reverse the symbol.
to f nd how many hours he must work
in a week to earn more than $100?
Answer x ≤ –35 Check this result. A. 6x < 100
B. 6x ≥ 100
Graph the solution x ≤ –35.
C. 6x ≤ 100
D. 6x > 100

Answer
-37 -36 -35 -34 -33

Solve –9x < –27 and check your solution. Then
graph the solution on a number line.

–9x < –27 Write the inequality.
9x -27 Divide each side by –9 and
>
-9 -9 reverse the symbol.

Answer x > 3 Check this result.

Graph the solution x ≤ –35.

1 2 3 4 5

163