Simplify by combining LIKE terms. Prove the new expression is equal to the original expression by substituting values for the variables.

1. 3A + 9A + A =

2. 10B - 4B =

3. 3C + -9C =

4. 8D - -5D =

5. 3E + 8E + -4E =

6. 4X + 8Y + -3X =

7. 7a + 6c + 5c =

8. -5h + 5k + -3k + 2h=

9. 3 + 2x + -7 =

10. 7 + 3a + -4a + 4 =

Simplify by using the "Distributive Property". Prove the new expression is equal to the original expression by substituting values for the variables. HINT: Think "value meals and a la carte".

11. 3(5 + x) =

12. 2(3x + 4) =

13. 7(3a - 2) =

14. 4(2h + 3f) =

15. 5(8k - 2y) =

16. 3(2a - 6) =