分解因式 x-y-x²+2xy-y²+2

分类: 作业答案 • 2022-03-20 23:55:01

问题描述：

答

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