merci d’avance pour ceux qui m’aide :)

Bonjour
2x + 5 = - 5x - 5
2x + 5x = - 5 - 5
7x = - 10
x = - 10/7
4 (3x - 5) = 3 + 2 (x - 1)
12x - 20 = 3 + 2x - 2
12x - 2x = 3 - 2 + 20
10x = 21
x = 21/10
2x/3 = (x + 6) / 5
10x = 3x + 18
10x - 3x = 18
7x = 18
x = 18/7.