ĐKXĐ: x>0 , x khác 1
[tex]\left ( \frac{1}{\sqrt{x}\left ( \sqrt{x}-1 \right )} +\frac{1}{\sqrt{x}-1}\right )/\frac{\sqrt{x}}{\left ( \sqrt{x}-1 \right )^{2}}[/tex]
= [tex]\frac{\sqrt{x}+1}{\sqrt{x}\left ( \sqrt{x}-1 \right )}.\frac{\left ( \sqrt{x}-1 \right )^{2}}{\sqrt{x}}[/tex]
=[tex]\frac{x-1}{x}[/tex]