simplify each expression.

1. 3x + 2(5x - 7)
2. 9 - 3(2x - 4)
3. 8x - 6(3 - 2x)
4. -5 + 5(x + 4)
5. 4 (6n + 9) - 10n
6. 14 - 3(4n - 1)
7. -8n + 8(4 + 2n)
8. 7k - 2(3k + 1) - 9
9. k + 1 - 4(2k - 9)
10. -6 + 5(8 - k) - 8k
11. -10k - 3 + 2(5 + 6k)
12. 8 + 9x + 4(11 - 2x)
13. -4(2x - 7) + 6x - 7
14. 9 + 3(4 - 3x) + 12x
15. 5(2y - 4) + 2(y + 9)
16. -4(3u - 1) +7(3 - 2u)
17. 6(-5u + 1) - 3(4u - 12)
18. -3(u + 5) + 8(2u + 1)