Solving equations with word problems - 7th grade math

1. 2b Solve equations that represent algebraic and real-world problems using multiple methods including the real number properties. (DOK 1) By: Deia Sanders

2. Solving Equations Ask yourself 2 questions What operation did they use? What is the inverse (opposite)? Then solve the problem!

3. Solving One-Step Equations involves application of the Inverse Operations of Addition/Subtraction and Multiplication/Division. Inverse operations are “opposite” operations. Addition is the “opposite” of subtraction. Subtraction is the “opposite” of addition. Multiplication is the “opposite” of division. Division is the “opposite” of multiplication. All equations are solved using inverse operations.

4. Examples Ask yourself 2 questions What operation did they use? What is the inverse (opposite)? Then solve the problem! X + 2 = 3 X + 2 – 2 = 3 – 2 X = 1 X – 2 = 3 X – 2 + 2 = 3 + 2 X = 5

5. More Examples Ask yourself 2 questions What operation did they use? What is the inverse (opposite)? Then solve the problem! 6a = 42

6. Additional Examples Y + 3 = 7 a- 6 = 8 3x = 33 X + 8 = 12 3b = 27

7. Handout #1 page 117 Solving one-step equations

8. Solving Two-Step Equations

9. Solving Two-Step Equations Strategy: A Sad Day is Monday Add Subtract Divide Multiply 2a + 3 = 15

10. Examples 2a + 3 = 15 Add Subtract Divide Multiply

11. Additional Examples Add Subtract Divide Multiply 2b – 7 = 15 4 + 5c = 15 5b – 8 = 7 2b + 3 = 23

12. Handout #2 Page 119

13. Word Problems

14. Word Problems Strategies for solving word problems: • Draw a picture, make a model, or act it out. • Work backwards from the answer. • Make a table or systematic list. • Estimate, check, and revise. • Look for a pattern. • Solve a simpler related problem. • Eliminate possibilities.

15. Example John earned $287 from mowing yards. He spent his money to buy 4 pair of blue jeans at a cost of b dollars each and concert tickets that cost $95. What was the cost of each pair of jeans? (K) List/underline key words. (A) What is the problem asking? What do you have to find? (S) What strategies could you use to answer the questions? (E) What answer choices could you eliminate and why?

16. Example Kendrick visited the Bulldog Video Store and spent a total of $14. A membership costs m dollars. It costs $4 to rent one video. If Kendrick rented two videos the same night that he purchased his membership, what is the cost of the membership? (K) List/underline key words. (A) What is the problem asking? What do you have to find? (S) What strategies could you use to answer the questions? (E) What answer choices could you eliminate and why?

17. Example Sara and Ray purchased a new stove for their home. The stove cost $388. They paid $100 down and then paid the rest in 6 equal payments. Approximately how much is each payment? (K) List/underline key words. (A) What is the problem asking? What do you have to find? (S) What strategies could you use to answer the questions? (E) What answer choices could you eliminate and why?

18. Handout #3 page 121