Expanding brackets

e.g.

<math>3(x + 4y) = 3x + 12y</math>

Simplify the following expressions…

1. 2(x + y)
2. 3(x + 2y)
3. 2(2x + 2y)
4. 5(x - 2y)
5. -2(2x + y)
6. -3(x - 2y)
7. -3(-3x + 2)
8. 5(x - 2y) - 2x
9. 4(x - y) - 2(x + 2y)
10. 3(2x + y) + 2(x - 2y)
11. (x - y) - a(x + 2y)
12. 2x + 3y - (x - 3y)
13. 5(x - 2y - z) + 3(x - y + 2z)
14. 3(x + 8) - 4(2x - 5)
15. x(x + 1)
16. x²(x - 7)
17. x³(x - 7) - x
18. x(x - 4) + 3(x - 2)
19. x(2x + 3) - 4(3x - 1)
20. x(x² + 1) - x²(x + 1)