Bonjour !

1- 5x - 3 = 2x + 9

2- 8 (x + 4) -2 (3x + 2) = 0

3- (7x - 4) (9x + 18) = 0


J'ai fait ceci :

1- 5x - 3 = 2x + 9
-2x + 5x - 3 = 9
3x = 12
x = 12/3
x = 4

2- 8( x + 4) -2 (3x + 2 ) = 0
8x + 32 - 6x - 4 = 0
8x - 6x = 0 + 4 - 32
2x = -28
x = -28/2
x = -14

3- 7x - 4 = 0            9x + 18 = 0
7x = 4                          9x = -18
x = 4/7                         x = -18/9

Merci de bien vouloir m'aider.