Bonjour
Résoudre :
3x + 12 = 0
3x = -12
x = -12/3
x = -4
x/2 - 5 = 0
x/2 = 5
x = 5 * 2
x = 10
5x + 7 = 12
5x = 12 - 7
x = 5/5
x = 1
5x + 7 = x + 3
5x - x = 3 - 7
4x = (-4)
x = -4/4
x = (-1)
x^2 = 25
x^2 - 25 = 0
x^2 - 5^2 = 0
(x - 5)(x + 5) = 0
x - 5 = 0 ou x + 5 = 0
x = 5 ou x = -5
2x^2 - 98 = 0
2(x^2 - 49) = 0
x^2 - 7^2 = 0
(x - 7)(x + 7) = 0
x - 7 = 0 ou x + 7 = 0
x = 7 ou x = -7
(x - 3)(x + 5) = 0
x - 3 = 0 ou x + 5 = 0
x = 3 ou x = -5
Developper :
3(x - 4) = 3 * x - 3 * 4 = 3x - 12
x(2x + 6) = x * 2x + x * 6 = 2x^2 + 6x
4x(x^2 - 5x + 6) = 4x * x^2 - 4x * 5x + 4x * 6 = 4x^3 - 20x^2 + 24x
