2 5 Addition and Subtraction Equations Important points

2 -5 Addition and Subtraction Equations Important points to remember: 1. ) Use the opposite operation to solve 2. ) What you do to one side of the equation you 
must do to the other side of the equation 3. ) Always check your answer

Two ways to show your work. Use the horizontal method for number 1 and 2. 1. ) m + 4 = 15 . ) w - 7 = 24 Use the vertical method for number 3 and 4. 3. ) y + 345 = 567 . ) p - 45 = 238

Rewrite the problem so there is only one sign in numbers 5 and 6. 5. ) c + (-4) = -5 . ) w - (-3) = -9 Sometimes it is easier to change the order of the problem. numbers 7 -9 so the variable is first and the answer is last. 7. ) -12 + w = 15 . ) -49 = b � 12 9. ) -10 + x = -2    10. ) a � 7 = -32 Rewrite the 
problem in

Word Problems Steps: 1. ) Identify what the variable represents 2. ) Write and solve the equation. 3. ) Write your answer in a sentence 1. ) Susan's math teacher assigned x homework problems on 
Monday. On Tuesday, she assigned 15 problems. Over the 
two days, a total of 24 homework problems were assigned. Write an 
equation and solve the equation to find the number of problems she 
assigned on Monday. 2. )You pay $1. 70 for a box of oatmeal after using a coupon for $. 80 off. Find the regular price of the oatmeal.

Demonstrate Understanding: Solve each 11. ) q � 15 = -27    2. ) x + (-4) = 29 13. ) w �(-19) = -8   4. ) 29 + y = -36 15. ) -17 + w = 7    6. ) -14 + a = -2 17. ) y + (-34) = -4   8. ) p � 15 = -7 19. ) -r + 12 = 5   20. ) w + (-18) = -2

Steps: 1. ) Identify what the variable represents 2. ) Write and solve the equation. 3. ) Write your answer in a sentence 21. ) There are 160 players in a soccer league. This is 23 more than last year. Find the number of players that were in the soccer league last year. 22. ) You spend $12. 75 at the movie theater. You purchase a ticket, a container of popcorn for $3. 25, and a bottle of water for $2. How much does the movie ticket cost?