Question

化简：

x-1

x

÷(x-

1

x

)，并求出当x=

1

2

时的值．

Answer 1

x-1

x

÷(x-

1

x

)=

x-1

x

÷

x2-1

x

=

x-1

x

×

x

(x+1)(x-1)

=

1

x+1

．…（3分）
当x=

1

2

时，原式=

1

1 2 +1

=

2

3

．…（2分）