通分“1/(x+y)和1/(x-y)”

问题描述:

通分“1/(x+y)和1/(x-y)”
用初二先最简公分母的方法


最简公分母为:(x+y)(x-y)
∴1/(x+y)=(x-y)/(x+y)(x-y)
1/(x-y)=(x+y)/(x+y)(x-y)