ab-b^2=b(a-b)
c^2-c=c(c-1)
x^3-2x^4+3x^5=x^3(3x^2-2x+1)
3x+6xy+9x^2=3x(1+2y+3x)
2(x-y)-a(x-y)=(2-a)(x-y)
7(x+y)-a(x+y)=(7-a)(x+y)
2(a-b)+c(b-a)=(2-c)(a-b)
2a(b-3)-5c(3-b)=(2a+5c)(b-3)
ab-b^2=b(a-b)
c^2-c=c(c-1)
x^3-2x^4+3x^5=x^3(3x^2-2x+1)
3x+6xy+9x^2=3x(1+2y+3x)
2(x-y)-a(x-y)=(2-a)(x-y)
7(x+y)-a(x+y)=(7-a)(x+y)
2(a-b)+c(b-a)=(2-c)(a-b)
2a(b-3)-5c(3-b)=(2a+5c)(b-3)