$$\sqrt{x}; (\sqrt{x}-\sqrt{x-5}); 2/nx; \sqrt{x}$$
$-\sqrt{x\left(x-\sqrt{x-5}\right)}+x$
$\frac{-\left(2\sqrt{x-5}-1\right)x+4\sqrt{x\left(x-5\right)\left(x-\sqrt{x-5}\right)}-2\sqrt{x-5}\left(x-\sqrt{x-5}\right)}{4\sqrt{x\left(x-5\right)\left(x-\sqrt{x-5}\right)}}$
