=x²-2xy-2x+xy-2y²-2y-x+2y+2=x(x-2y-2)+y(x-2y-2)-(x-2y-2)=(x-2y-2)(x+y-1)=x³-x²+2x²-2x-2x+2=x²(x-1)+2x(x-1)-2(x-1)=(x-1)(x²+2x-2)