Bonjour,
3x + 5 = 6x - 1
3x + 5 -6x = -1
3x -6x = -1 - 5
-3x = -6
x = -6 / -3
x = 2
6x - 2 = 4 (x -3)
6x - 2 = 4x -12
6x - 2 -4x = -12
6x - 4x = -12 + 2
2x = -10
x = -10 / 2
x = - 5
-7x - 12 = -2(-5 -1)
-7x - 12 = 10 + 2
-7x = 12 + 12
x = 24 / -7
x = [tex]-\frac{24}{7}[/tex]