а) ab-7a+3b-21
б) 6x³+3x²-2x-1
в) x³-x²-3x+2x²-2x-6= x³+x²-5x-6
г) -4(y²+5y-y-5)= -4(y²+4y-5)= -4y²-16y+20
8p-(6p²-15p+16p-40)= 8p-(6p²+p-40)= 8p-6p²-p+40= -6p²+7p+40
а) ab-7a+3b-21
б) 6x³+3x²-2x-1
в) x³-x²-3x+2x²-2x-6= x³+x²-5x-6
г) -4(y²+5y-y-5)= -4(y²+4y-5)= -4y²-16y+20
8p-(6p²-15p+16p-40)= 8p-(6p²+p-40)= 8p-6p²-p+40= -6p²+7p+40