(1) (x^-1)+(y^-1)分之(x^-2) - 知识问答

(1) (x^-1)+(y^-1)分之(x^-2)-(y^-2) (2) (y-x^-1)除以（x-y^-1) 一共两道

1个回答

(1)
原式=（1/x+1/y)/(1/x²-1/y²)
=(1/x+1/y)/[(1/x+1/y)(1/x-1/y)]
=1/(1/x-1/y)
=xy/(y-x)
(2)
原式=(y-1/x)/(x-1/y)
=[(xy-1)/x]/[(xy-1)/y]
=(1/x)/(1/y)
=y/x

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