问题 填空题

分解因式:x2+x-y2-y=______.

答案

x2+x-y2-y

=x2-y2-y+x

=(x-y)(x+y)-(x-y)

=(x-y)(x+y-1).

故答案为:(x-y)(x+y-1).

选择题
名词解释