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)