因式分解x(x+y)(x-y)-x(x+y)^2
问题描述：
因式分解x(x+y)(x-y)-x(x+y)^2
答
x(x+y)(x-y)-x(x+y)^2
=x(x+y)[(x-y)-(x+y)]
=x(x+y)(x-y-x-y)
=-2xy(x+y)