1) а) а(b-c)+y(b-c)=(b-c)(a+y)
б) а²b²(a+1)-a(a+1)=(a+1)(a²b²-a)=a(ab²-1)(a+1)
2) -3x²-5x-6=x+4-3x²-12x
-3x²+3x²-5x+12x-x=4+6
6x=10
x=10/6
x=5/3
3) 4x²-5x-12x+15-4x²-1=14-17x
4) 4x³-5x²-x-8x²+10x+2=4x³-13x²+9x+2
5) x²(x²-y²)-2(x²-y²)-a(x²-y²)=(x²-y²)(x²-2-a)=(2²-3²)(2²-2-1)=(4-9)(4-3)=-5*1=-5