Répondre :
A=(-10x+1) (4x-9)
=-40x²+90x+4x-9
=-40x²+94x-9
B= (2x+5) (-x+2) - (x-3) (-3x+4)
=-2x²+4x-5x+10-(-3x²+4x+9x-12)
=-2x²+4x-5x+10+3x²-4x-9x+12
=x²-14x+22
=-40x²+90x+4x-9
=-40x²+94x-9
B= (2x+5) (-x+2) - (x-3) (-3x+4)
=-2x²+4x-5x+10-(-3x²+4x+9x-12)
=-2x²+4x-5x+10+3x²-4x-9x+12
=x²-14x+22