1. Objectives The student will be able to: 1. solve equations using addition and subtraction. SOL: A.1, A.3 Designed by Skip Tyler, Varina High School

2. 1) Solve r + 16 = -7 Think of this as a balanced scale. On one side, you have r + 16. On the other side, you have -7. The equal sign means that it is balanced now. If you put something on one side, you must put the same thing on the other to keep it balanced.

3. 1) Solve r + 16 = -7 The objective is to get the variable by itself. What number is on the same side as the variable? 16 We must move the 16 to the other side.

4. 1) Solve r + 16 = -7 Instead of adding 16, we do the opposite Subtract 16 from both sides r + 16 - 16 = -7 - 16 Simplify the problem. r = -23

5. Check your answer. Put -23 back into the original problem in the place of r. -23 + 16 = -7 -7 = -7 √ You can check every answer to see if you are right!!

6. 2) Solve x + 2 = -3 Get the variable by itself. What number is on the same side as the variable? 2 Do the opposite of adding 2 x + 2 - 2 = -3 - 2 x = -5

7. Check your answer. -5 + 2 = -3 -3 = -3 √ On homework and tests, be sure to check your work!! There is no reason why you should miss a problem!

8. 3) Solve 8 = m - 3 8 + 3 = m - 3 + 3 11 = m Check: 8 = 11 - 3 8 = 8 √

9. 4) Solve y + (-3) = 7 Rewrite + (- ) with 1 sign + (- ) = - and - (- ) = + y - 3 = 7 y - 3 + 3 = 7 + 3 y = 10 Check: 10 + (-3) = 7 7 = 7 √

10. 5) Solve -x - (-2) = 1 Rewrite: -x + 2 = 1 -x + 2 - 2 = 1 - 2 -x = -1 “The opposite of x equals -1” x = 1 Check -(1) + 2 = 1 1 = 1 √