(x/x-y减y/y-x)除以x+y/xy 初二的分式的运算
问题描述：
(x/x-y减y/y-x)除以x+y/xy 初二的分式的运算
答
原式
=[x/(x-y)+y/(x-y)]*xy/(x+y)
=(x+y)(x-y) *xy(x=y)
= xy/(x-y)
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