Solve the following equation:

7x + 8 - 2x = 20

Solve the following equation:

0.5(2x + 14) = 10

Solve the following equation:

-3x = 9

Solve the following equation:

x + 18 = 20

Solve the following equation:

 $\frac{1}{2}x\ -\ 4\ =\ 10$  

Solve the following equation:

 $-2\left(3x\ -\ 7\right)\ =\ 2x\ -\ 2$