Explications étape par étape:
a)
4x + (3x-1) - 3 = 8x - 2x + 4
7x - 4 = 6x + 4
7x - 6x = 8
x = 8
b)
5x - (x - 4) = 20
5x - x + 4 = 20
4x = 20 - 4 = 16
x = 4
c)
3 - (8x + 1) = 2x - 4
2 - 8x = 2x - 4
2 + 4 = 2x +8x
6 = 10x
x = 3/5
d)
(x - 2) + (-x - 4) = 5x + (-2x + 16)
-6 = 3x + 16
3x = - 16 - 6 = - 22
x = - 22/3