bonjour
7 x + 2 = 2 x + 3
7 x - 2 x = 3 - 2
5 x = 1
x = 1 /5
8 ( 9 - x ) = 10 x + 4
72 - 8 x = 10 x + 4
- 8 x - 10 x = 4 - 72
- 18 x = - 68
x = 68/18 = 34/ 9
( 5 x + 6 ) ( 3 x - 9 ) = 0
x = - 6 /5 ou 9 /3 = 3
(4x+1)(3x-7)=(6x+8)(2x-1)
12 x² - 28 x + 3 x - 7 = 12 x² - 6 x + 16 x - 8
12 x² - 12 x² - 25 x + 6 x - 16 x = - 8 + 7
- 35 x = - 1
x = 1/35
