Réponse:
Bonjour
Explications étape par étape:
a) A = (4x+3)² - (5-2x)²
= (4x² +2×4x×3 +3²) - (5²- 2×5×2x + 2x²)
= 16x² +24x +9 -(25 -20x + 4x²)
= 16x² +24x +9 -25 +20x -4x²
= 12x² +44x -16
b) B = (x+6)(3-9x) - (x+6)(6x-7)
= (x+6)(3-9x-(6x-7))
= (x+6)(3-9x-6x+7)
= (x+6)(10-15x)
= (x+6)5 × (2-3x)
= 5(x+6)(2-3x)
