Bonsoir '
A = (x+1)(x+2)+(x+1)(2x-3)
A = (x+1)(x+2+2x-3)
A = (x+1)(3x-1)
B = (3x-1)(x+2)-(3x-1)(3x+1)
B = (3x-1)(x+2-3x-1)
B = (3x-1)(-2x+1)
C = (1-2x)(2x+3)+(1-2x)(3x+2)
C = (1 -2x)(2x+3+3x+2)
C = (1-2x) (5x+5)
D = (2x+3)(2x-3)-(4x-5)(2x-3)
D = (2x-3)(2x+3-4x+5)
D = (2x-3)(-2x+8)
Bonne soirée.