Réponse :
Exercice 2
A = (2x+3)² = 3² + 2*3*2*x+(2*x)²
= 9² +12x+4x²
B= (4-3x) ² = (-3*x)² +2*4*(-3*x)+4²
= 16-24x+ 9x²
Exercice 3
A= (2x+1)² +(4x-3)(5x+2)
= 2²*x² +4*x*5*x+4*x-(3*5*x+3*2)
= -7x-6+24x²
B= (x+1)² -(x+1)(3x-5)
= (1+2*x+x² -(x*3*x-x*5+3*x-5)
= 6+4x-2x²
(les * correspondent a des multiplications et les x au nombre "x")
