Sagot :
a) (3x+2)^2 = 3x^2 +2 X 3x X 2 + 2^2 = 6x^2 +12x + 4
(5-2x)(3x+2) = 5x3x +2x5 -6x^2 + 2x2 = 15x + 10 - 6x^2 +4
6x^2 +12x + 4 - 15x + 10 - 6x^2 +4 = -3x + 18
b) 3(-1x + 6)
c) tu remplaces tout les x par -2 et c'est très facile :)
bonsoir
1)
E = (3x+2)² -(5-2x)(3x+2)
E = 9x²+12x+4 -15x-10+6x²+4x
E = 15x²+x-6
2)
E =(3x+2)(3x+2) -(5-2x)(3x+2)
E = (3x+2)(3x+2-5+2x)
E = (3x+2)(5x-3)