(x-y分之1+x+y分之1)除以x的平方-y的平 - 知识问答

(x-y分之1+x+y分之1)除以x的平方-y的平方分之x的平方y

1个回答

解
[1/(x-y)+1/(x+y)]÷[x²y/(x²-y²)]————是这个吗?
=[1/(x-y)+1/(x+y)]×[(x-y)(x+y)/x²y]
=[(x+y)/x²y+(x-y)/x²y]
=(x+y+x-y)/x²y
=2x/x²y
=2/xy

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