Réponse:
( 5x - 1 ) ( 2 - 3x ) = 0
revient à résoudre
5x - 1 = 0.
2 - 3x = 0
x = 1/5
x = 2/3
2x - 4 = 2 + 3x
2x - 4 - 3x = 1
- x -4 = 1
- x = 1 + 4
- x = 5
x = - 5
9x + 14 = 7x + 42
9x + 14 - 7x = 42
2x + 14 = 42
2x = 42 - 14
2x = 28
x = 28/2
x = 14
3x <= 12
x <= 12/3
x <= 4
