Solve the following equations :

1.

3a + 7 = 28

2.

4b - 3 = 9

3.

8c + 7 = 23

4.

6x + 8 = 2x - 12

5.

4x - 7 = 9x + 8

6.

13x - 12 = 5 - 4x

7.

7y + 18 = 6 - 5y

8.

3a - 4 = 20 - 9a

9.

9y + 4 = 16 - 3y

10.

7x + 12 = 2(3x - 7)

11.

3x = 8(x + 3) - 9

12.

2(a - 5) = 12a + 20

13.

4(b + 3) = 13b - 24

14.

5(c + 3) = 24 - 10c

15.

7(3 - m) = 24 - 13m