1) 6x + (3x - 4) = 14
6x + 3x - 4 = 14
9x - 4 = 14
9x = 14 + 4
9x = 18
x = 2
2) 8y - (5y - 24) = 51
8y - 5y + 24 = 51
3y + 24 = 51
3y = 51 - 24
3y = 27
y = 9
3) (6x + 1) - (3 - 2x) = 14
6x + 1 - 3 + 2x = 14
8x - 2 = 14
8x = 14 + 2
8x = 16
x = 2
4) 6y - 20 = 2 (5y - 10) - 4
6y - 20 = 10y - 20 - 4
6y = 10y - 4
6y - 10y = - 4
- 4y = - 4
y = 1
5) 7 (3 + x) = 2 (x - 5) + 6
21 + 7x = 2x - 10 + 6
21 + 7x = 2x - 4
7x - 2x = - 4 - 21
5x = - 25
x = - 5
6) 15 (x + 2) - 10 = 10x
15x + 30 - 10 = 10x
15x + 20 = 10x
15x - 10x = - 20
5x = - 20
x = - 4