因式分解：x的平方-xy-2y的平方+2x-y+1

x²-xy-2y²+2x-y+1=x²+2x+1-xy-y-2y² =(x+1)²-y(x+1)-2y² =(x+1)²-y²-y(x+1)-y² =[(x+1)-y]*[(x+1)+y]-y[(x+1)+y] =(x-y+1)(x+y+1)-y(x+y+1) =(x+y+1)[(x-y+1)-y] =(x+y+1)(x-2y+1) 祝你开心!希望能帮到你,如果不懂,请追问,祝学习进步!O(∩_∩)O