Réponses

2013-10-17T20:17:21+02:00
B=(-x+2)(3x-4)+(-x-7)(2x-1)
=-3x²+4x+6x-8-2x²+1-14x+7
=-5x²-4x-1

C=(2x-5)(8-x)-(3x+1)(x-6)
=16x-2x²-40+5x-(3x²-18x+x-6)
=16x-2x²-40+5x-3x²+18x-x+6
=-5x²+39x-34