Đáp án:
$\begin{array}{l}
Dkxd:x \ge 0;x \ne 1\\
A = \dfrac{{2x + \sqrt {9x} - 3}}{{x + \sqrt x - 2}} - \dfrac{{\sqrt x + 1}}{{\sqrt x + 2}} - \dfrac{{\sqrt x - 2}}{{\sqrt x - 1}}\\
= \dfrac{{2x + 3\sqrt x - 3}}{{\left( {\sqrt x - 1} \right)\left( {\sqrt x + 2} \right)}} - \dfrac{{\sqrt x + 1}}{{\sqrt x + 2}} - \dfrac{{\sqrt x - 2}}{{\sqrt x - 1}}\\
= \dfrac{{2x + 3\sqrt x - 3 - \left( {\sqrt x + 1} \right)\left( {\sqrt x - 1} \right) - \left( {\sqrt x - 2} \right)\left( {\sqrt x + 2} \right)}}{{\left( {\sqrt x + 2} \right)\left( {\sqrt x - 1} \right)}}\\
= \dfrac{{2x + 3\sqrt x - 3 - x + 1 - x + 4}}{{\left( {\sqrt x + 2} \right)\left( {\sqrt x - 1} \right)}}\\
= \dfrac{{3\sqrt x + 2}}{{\left( {\sqrt x + 2} \right)\left( {\sqrt x - 1} \right)}}
\end{array}$
