指數數學題

(x^-1-y^-1)^-1

首先入面要轉換成分數

然後通分母

得出(x-y)/xy

然後因為負一次方, 所以分子分母掉轉

=[(1/x)-(1/y)]^-1

=[(x-y)/xy]^-1

=1/[(x-y)/xy]

=xy/x-y

(x^-1-y^-1)^-1
=[(1/x)-(1/y)]^-1
=[(x-y)/xy]^-1
=1/[(x-y)/xy]
=xy/x-y

Hope i can help you.