Directions: Simplify by combining like terms in each of the following expressions.

1. 10s2 + 10s2 - 13st =

2. 13st + - 2st - t2 =

3. x2+ x2 + x3=

4. 6 x - 6 x + 2=

5. 24x - 3s - 4t=

6. 86 + 86x - 1 =

7. 4x + 3x - 2 =

8. 7s - 4s + 3s =

9. 12 +11x - 10 x =

10. 12x + 24 x - 3 x - 4 =

11. 16t + 8t - 12t =

12. 17g + 19g - 2g +g =

13. 16 + 16 -16 + 16x =

14. 4s - 3s + 3s =

15. 12t - 11t + t =