Développe : b(x) = (x+6)² + (x+2)(4x-3)
factorisé : (x+7)(2x+1) + (x+7)(x+5)
factorisé : (x+3)² - 2(x²-9)
B(x) = (x²+12x+36) + (4x²-3x+8x-6)
= x²+12x+36+4x²+5x-6
= 5x²+17x+30
Factorisation
(x+7)(2x+1)+(x+5)
= (x+7)(2x+1+x+5)
= (x+7)(3x+6)
(x+3)(x+3)-2(x-3)
= (x+3)(x+3-2x-6)
= (x+3)(-x-3)