Sagot :
A = (6x²-21x-10x+35) - (6x-5)
= 6x² -31x+35-6x+5
= 6x²-37x+40
B = (18x²-24x-15x+20) - (25x²+20x+4)
= 18x²-39x+20-25x²-20x-4
= -7x²-59x+16
C = (20x²-4x+15x20x-3) - (45x²+25x-9x-5)
= 20x²-31x-3) - (45x²+16x-5)
= 20x²-31x-3-45x²-16x+5
= -25x²-47x+2
D = 10x+25(3x-2)
= 10x+75x-50
= 85x-50
E = 6x+2(2x+5) - (42x²-18x-7x+3)
= 6x+4x+10-42x²+18x+7x-3
= -42x²35x+7
F = (2x²-2x+3x-3)(4x-5)
= 2x²+x-3 (4x-5)
= 8x^3-10x²+4x²-5x-12x+15
= 8x^3-6x²-17x+15
A = (6x²-21x-10x+35) - (6x-5)
= 6x² -21x-10+35-6x+5
=6x²-31x+35-6x+5
= 6x²-37x+40
B = (18x²-24x-15x+20) - (25x²+20x+4)
= 18x²-24x-15x+20-25x²-20x-4
=18x²-39x+20-25x²-20x-4
= -7x²-59x+16
C = (20x²-4x+15x20x-3) - (45x²+25x-9x-5)
= 20x²-31x-3) - (45x²+16x-5)
= 20x²-31x-3-45x²-16x+5
= -25x²-47x+2
D = 10x+25(3x-2)
= 10x+75x-50
= 85x-50
E = 6x+2(2x+5) - (42x²-18x-7x+3)
= 6x+4x+10-42x²+18x+7x-3
= -42x²+35x+7
F = (2x²-2x+3x-3)(4x-5)
= 2x²+x-3 (4x-5)
= 8x^3-10x²+4x²-5x-12x+15
= 8x^3-6x²-17x+15