Lesson 13
Reintroducing Inequalities
Let’s work with inequalities.
Problem 1
For each inequality, find two values for \(x\) that make the inequality true and two values that make it false.
 \(x+3>70\)
 \(x+3<70\)
 \(\text5x<2\)
 \(5x<2\)
Problem 2
Here is an inequality: \(\text3x > 18\).
 List some values for \(x\) that would make this inequality true.
 How are the solutions to the inequality \(\text3x \geq 18\) different from the solutions to \(\text3x > 18\)? Explain your reasoning.
Problem 3
Here are the prices for cheese pizza at a certain pizzeria:
pizza size  price in dollars 

small  11.60 
medium  
large  16.25 

You had a coupon that made the price of a large pizza $13.00. For what percent off was the coupon?

Your friend purchased a medium pizza for $10.31 with a 30% off coupon. What is the price of a medium pizza without a coupon?

Your friend has a 15% off coupon and $10. What is the largest pizza that your friend can afford, and how much money will be left over after the purchase?
Problem 4
Select all the stories that can be represented by the diagram.
Andre studies 7 hours this week for endofyear exams. He spends 1 hour on English and an equal number of hours each on math, science, and history.
Lin spends $3 on 7 markers and a $1 pen.
Diego spends $1 on 7 stickers and 3 marbles.
Noah shares 7 grapes with 3 friends. He eats 1 and gives each friend the same number of grapes.
Elena spends $7 on 3 notebooks and a $1 pen.