约分x^3-y^3/x^2-y^2有过程
问题描述：
约分x^3-y^3/x^2-y^2
有过程
答
x^3-y^3/x^2-y^2=（x-y）(x^2+xy+y^2)/(x-y)(x+y)
=(x^2+xy+y^2)/(x+y)
=(x+y)-xy/(x+y)