把多项式x^2-x+y-y^2因式分解,结果为
问题描述：
把多项式x^2-x+y-y^2因式分解,结果为
答
x^2-x+y-y^2
= x²- y² - (x-y)
= (x+y)(x-y) - (x-y)
= (x+y-1 )( x-y)