(x+y)(x-1)-xy-y^2 怎么因式分解?
问题描述:
(x+y)(x-1)-xy-y^2 怎么因式分解?
答
(x+y)(x-1)-xy-y^2
=x^2-x+xy-y-xy-y^2
=(x^2-y^2)-(x+y)
=(x+y)(x-y)-(x+y)
=(x+y)(x-y-1)