分解因式:1-x2+2xy-y2=_.
问题描述:
分解因式:1-x2+2xy-y2=______.
答
原式=1-(x2-2xy+y2)
=1-(x-y)2
=(1+x-y)(1-x+y).
故答案为(1+x-y)(1-x+y).