已知 $x+\frac{1}{x}=5(0<x<1)$, 则 $\sqrt{x}-\frac{1}{\sqrt{x}}=$ \$ \qquad \$ .
$\because x+\frac{1}{x}=5(0<x<1)$,

$$
\begin{aligned}
& \therefore \sqrt{x}<\frac{1}{\sqrt{x}} \\
& \therefore\left(\sqrt{x}-\frac{1}{\sqrt{x}}\right)^{2} \\
& =x-2+\frac{1}{x}
\end{aligned}
$$

$=3$,

$\therefore \sqrt{x}-\frac{1}{\sqrt{x}}=-\sqrt{3}$,

故答案为: $-\sqrt{3}$.