Đáp án:
$\begin{array}{l}
Dkxd:x \ge 0;x \ne 1\\
P = \dfrac{{\sqrt x + 1}}{{2\sqrt x - 2}} - \dfrac{{\sqrt x - 1}}{{2\sqrt x + 2}} - \dfrac{2}{{\sqrt x - 1}}\\
= \dfrac{{\sqrt x + 1}}{{2\left( {\sqrt x - 1} \right)}} - \dfrac{{\sqrt x - 1}}{{2\left( {\sqrt x + 1} \right)}} - \dfrac{4}{{2\left( {\sqrt x - 1} \right)}}\\
= \dfrac{{\sqrt x - 3}}{{2\left( {\sqrt x - 1} \right)}} - \dfrac{{\sqrt x - 1}}{{2\left( {\sqrt x + 1} \right)}}\\
= \dfrac{{\left( {\sqrt x - 3} \right)\left( {\sqrt x + 1} \right) - {{\left( {\sqrt x - 1} \right)}^2}}}{{2\left( {\sqrt x - 1} \right)\left( {\sqrt x + 1} \right)}}\\
= \dfrac{{x - 2\sqrt x - 3 - x + 2\sqrt x - 1}}{{2\left( {x - 1} \right)}}\\
= \dfrac{{ - 4}}{{2\left( {x - 1} \right)}}\\
= \dfrac{2}{{1 - x}}
\end{array}$
