Réponse:
bonjour
Explications étape par étape:
1) A = (7x - 4)(5 – 3x) + (5x - 1)(8+2x)
A=35x-21x²-20+12x+40x+10x²-8-2x
=-11x²+85x-28
2) B = 3x(9-6x) + x(4x - 5)
=27x-18x²+4x²-5x
=-14x²+22x
3) C = (8a-5)(b -3) - (1 -3b)(4+ a)
=8ab-24a-5b+15-4-a+12b+3ba
=11ab-25a+7b+11
4) D= (5x - 2)2 + 10x(4x - 5)
=10x-4+40x²-50x
=40x²-40x-4
6) F= (5x – 4)(2x + 3) – (1 - x)2 - (2x - 5)(5 - x)
=10x+15x-8x-12-2+2x-10x+2x²+25-5x
=2x²+4x+11
7) G= -2m(-1-2n) + (2m + 1)(2m - 1)
=2m+4mn+4m²-2m+2m-1
=4m²+4mn+2m-1
8) H= -(x – 8)2 - 5x(6x - 10)
=-2x+16-30x²+50x
=-30x²+40x+16
