On considère l'expression suivante : E(x) = (x-5)(2x+3)-(2x+3)² Factoriser E

Bonjour,

E(x) = (x - 5)(2x + 3) - (2x + 3)^2

Factoriser :

E(x) = (2x + 3)(x - 5 - 2x - 3)
E(x) = (2x + 3)(-x - 8)

Developper :

E(x) = 2x^2 + 3x - 10x - 15 - (4x^2 + 12x + 9)
E(x) = -2x^2 - 19x - 24

E(x) = 0
(2x + 3)(-x - 8) = 0
2x + 3 = 0
2x = - 3
x = -3/2

Ou

-x - 8 = 0
x = -8