Réponse:
2x -x = 4
x = 4
3x -4 = 5x +2
3x -5x = 2 +4
-2x = 6
-2x/-2 = 6/-2
x= -3
6x -3 = 2x +2
6x -2x = 2+3
4x = 5
4x/4 = 5/4
x = 5/4
x² = 4
√x² = √4
x = 2
2x² = 50
2x²/2 = 50/2
x² = 25
√x² = √25
x = 5
(3x -6)(-2x +9) = 0
3x -6 =0
3x = 6
3x/3 = 6/3
x = 2
-2x +9 = 0
-2x = -9
-2x/-2 = -9/-2
x = 9/2
L'équation a deux solutions : 2 et 9/2