Page 16 - Math Course 3 (Book 1)

Multiplying and Dividing Linear Inequalities

Write an Inequality
Let’s Begin Example

Sports pennants are on sale for
Divide to Solve an Inequality $2.50 each. Which inequality can
be used to find how many sports
Examples pennants Amy can purchase for
herself and friends if she wants to
spend no more than $15?
Solve 12s > 60

12s > 60 Original inequality A. 2.50p ≥ 15 B. 2.50p ≤ 15
C. 2.50 ≤ 15p D. 2.50 ≥ 15p
12s > 60 Divide each side by 12 and
12 12 do not change the direction
of the inequality sign.
Read the Test Item
s > 5 Simplify. You want to find the inequality that represents the
number of pennants that can be purchased for $15
Answer The solution set is {s | s ≥ 5}. or less.

Solve the Test Item
If p represents the number of pennants, then 2.50p
Solve –8q < 136 represents the total cost of p pennants. So, you can
eliminate Choices C and D.
–8q < 136 Original inequality
No more than $15 indicates less than or equal to
–8q > 136 Divide each side by –8 and
–8 –8 change < to >. 15, so the inequality that represents the situation is
2.50p ≤ 15. The answer is B.
q > –17 Simplify.

Answer The solution set is {q | q > –17}. Answer B

Your Turn! Divide to Solve an Inequality
Solve 15p < 60.
Write an Inequality
A. {p | p < 4}
MOVIE TICKETS B. {p | p < 45}
Movie tickets cost $5.00 per person. Which C. {p | p < 75}
inequality can be used to find how many movie D. {p | p > 4}
tickets Janine can purchase for herself and
friends if she wants to spend no more than $50? Answer

A. 5p ≤ 50 Solve –4z > 64.
B. 5p ≥ 50
C. 5 ≤ 50p A. {z | z < 16}
D. 5 ≥ 50p B. {z | z < –16}
C. {z | z > –16}
D. {z | z > 16}

Answer
Answer

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