分解因式:(x+y)2-4(x+y-1)=_.
问题描述:
分解因式:(x+y)2-4(x+y-1)=______.
答
(x+y)2-4(x+y-1)
=(x+y)2-4(x+y)+4
=(x+y-2)2.
故答案为:(x+y-2)2.