bonsoir
1) (5x - 7) - (8x + 9) = 0
5 x - 7 - 8 x - 9 = 0
- 3 x = 9 + 7
- 3 x = 16
x = - 16 /3
2) (3x - 2)(5x + 4) = 0
il suffit que l'un des 2 termes soit nul donc x = 2/3 ou - 4/5
3) 5(5 - x) = 0
25 - 5 x = 0
- 5 x = - 25
x = 5
4) (2x + 3)² = 0
idem que le 2 , x = - 3/2
5) (2x - 5)2 = 49
2 x - 5 = 7
2 x = 7 + 5
2 x = 12
x = 6
6) x + 2 = ?
7) - 1 = 28-3 ?
