Bonjour,
Résoudre les équations-produit suivantes :
a) (2x + 1)(4x - 1) = 0
2x + 1 = 0 ou 4x - 1 = 0
2x = - 1 4x = 1
x = - 1/2 x = 1/4
b) (2x - 9) (-x - 2) = 0
2x - 9 = 0 ou - x - 2 = 0
2x = 9 - x = 2
x = 9/2 = 4,5 x = - 2
c) (3x - 5)(8 - 2x) = 0
3x - 5 = 0 ou 8 - 2x = 0
3x = 5 - 2x = - 8
x = 5/3 x = 8/2 = 4
d (10 - 4x) x 7 = 0
70 - 28x = 0
- 28x = 70
x = - 70/28
x = - 2,5.
2)
Résoudre chaque équation :
a) (3x + 1)(x - 5) = 0
3x + 1 = 0 ou x - 5 = 0
3x = - 1 x = 5
x = - 1/3
b) (3x + 7)(4x - 8) = 0
3x + 7 = 0 ou 4x - 8 = 0
3x = - 7 4x = 8
x = - 7/3 x = 8/4 = 2.
c 5(9x - 3)(-5x - 13) = 0
9x - 3 = 0 ou - 5x - 13 = 0
9x = 3 - 5x = 13
x = 3/9 = 1/3 x = - 13/5
