x²-xy+2x-y-3
=x(x-y)+(x-y)+x-3
=(x-1)(x-y)+x-3
=(x-1)(x-y-1)-2
x²-xy+2x+y-3
=x(x-y)-(x-y)+3(x-1)
=(x-1)(x-y)+3(x-1)
=(x-1)(x-y+3)