1. 6-7 Solving inequalities by Multiplication or division
7th grade Mathematics
6-7 Solving inequalities by Multiplication or division

2. Minute Math

4. Review
a + 4 > ) b – 5 < 12
3) 2c + 4 = ) 𝑑 4 −6=−3

5. I can solve inequalities involving multiplication or division.
7.EE.4
Use variables to represent quantities in a real-world or mathematical problems, and construct simple equations and inequalities to solve problems by reasoning about the quantities.
7.EE.4b
Solve word problems leading to inequalities of the form px+q>r or px+q<r where p, q, and r are specific rational numbers. Graph the solution set, and interpret it in the context of the problem.

6. Video

7. Solve: 8x < 40

8. Solve: 𝑑 2 >7

9. Your Turn!!!
4a < ≥ 𝑏 ≤ 5 𝑐

10. 7.EE.4
Use variables to represent quantities in a real-world or mathematical problems, and construct simple equations and inequalities to solve problems by reasoning about the quantities.
7.EE.4b
Solve word problems leading to inequalities of the form px+q>r or px+q<r where p, q, and r are specific rational numbers. Graph the solution set, and interpret it in the context of the problem.

11. When you multiply or divide each side of an inequality by a negative number, the inequality symbol must be reversed (flipped the other way) for the inequality to remain a true statement.
7 >1
(-1)7 < 1(-1)
-7 < -1

12. Why do we have to flip the symbol when dividing by a negative?
Think – Pair-SHare
Why do we have to flip the symbol when dividing by a negative?

13. Solve: −2𝑔<10 and graph on a number line

14. Solve: 𝑥 −3 ≤4 Graph the solution on a number line.

15. Your Turn!!!
Solve and graph
𝑘 −2 <9

16. 7.EE.4
Use variables to represent quantities in a real-world or mathematical problems, and construct simple equations and inequalities to solve problems by reasoning about the quantities.
7.EE.4b
Solve word problems leading to inequalities of the form px+q>r or px+q<r where p, q, and r are specific rational numbers. Graph the solution set, and interpret it in the context of the problem.

17. Jackie earns $8 per hour working at the zoo
Jackie earns $8 per hour working at the zoo. Write and solve an inequality that can be used to find how many hours she must work in a week to earn at least $120. Interpret the solution.

18. A plate weighs ¼ pound. A shelf can hold at most 20 pounds
A plate weighs ¼ pound. A shelf can hold at most 20 pounds. Write and solve an inequality to find how many plates the shelf can hold. Interpret the solution.

19. 7.EE.4
Use variables to represent quantities in a real-world or mathematical problems, and construct simple equations and inequalities to solve problems by reasoning about the quantities.
7.EE.4b
Solve word problems leading to inequalities of the form px+q>r or px+q<r where p, q, and r are specific rational numbers. Graph the solution set, and interpret it in the context of the problem

20. On your own
Complete the practice page. Make sure to show all your work. Keep when finished and have a red pen/pencil ready to check.

21. Solve each inequality and graph.
Exit Ticket
Solve each inequality and graph.
6y < ) -3q > ) 𝑤 −5 ≥9
4) A pool charges $4 each visit, or you can buy a membership for 3 months for $100. Write and solve an inequality to find how many time a person would use the pool so that a membership is less expensive than paying each time. Interpret the solution.