(xy-1)^2-(x+y-2xy)(2-x-y)

分类: 作业答案 • 2022-05-02 16:44:48

问题描述：

(xy-1)^2-(x+y-2xy)(2-x-y)
THANKS!

答

原式=(xy-1)^2+[(x+y)-2xy](x+y-2)
=[(xy-1)^2-4xy]+(x+y)^2-2xy(x+y)-2(x+y)
=(xy+1)^2-2(x+y)(xy+1)+(x+y)^2
=(xy+1-x-y)^2
=(x-1)^2*(y-1)^2