Réponse :
Explications étape par étape
Bonjour
Developper :
A = (x + 1)^3 + (x - 2)^3
A = (x + 1)(x + 1)^2 + (x - 2)(x - 2)^2
A = (x + 1)(x^2 + 2x + 1) + (x - 2)(x^2 - 4x + 4)
A = x^3 + 2x^2 + x + x^2 + 2x + 1 + x^3 - 4x^2 + 4x - 2x^2 + 8x - 8
A = 2x^3 - 3x^2 + 15x - 7
Factoriser :
B = x^3 + (x - 2)(3x - 5) - 8
B = x^3 - 8 + (x - 2)(3x - 5)
B = x^3 - 2^3 + (x - 2)(3x - 5)
x^3 - 2^3 = (x - 2)(x^2 + 2x + 4)
x^3 - 2^3 = (x - 2)(x + 2)^2
B = (x - 2)(x + 2)^2 + (x - 2)(3x - 5)
B = (x - 2)[(x + 2)^2 + 3x - 5]
B = (x - 2)(x^2 + 4x + 4 + 3x - 5)
B = (x - 2)(x^2 + 7x - 1)
