Đáp án:
$\begin{array}{l}
\dfrac{9}{{\sqrt {11} - \sqrt 2 }} + \dfrac{{\sqrt {22} - \sqrt {10} }}{{\sqrt {11} - \sqrt 5 }} - \dfrac{2}{{\sqrt {11} }}\\
= \dfrac{{9\left( {\sqrt {11} + \sqrt 2 } \right)}}{{11 - 2}} + \dfrac{{\sqrt 2 \left( {\sqrt {11} - \sqrt 5 } \right)}}{{\sqrt {11} - \sqrt 5 }} - \dfrac{{2\sqrt {11} }}{{11}}\\
= \sqrt {11} + \sqrt 2 + \sqrt 2 - \dfrac{{2\sqrt {11} }}{{11}}\\
= \dfrac{{9\sqrt {11} }}{{11}} + 2\sqrt 2 \\
\dfrac{7}{{\sqrt {10} - \sqrt 3 }} - \dfrac{{5\sqrt 2 - 2\sqrt 5 }}{{\sqrt 5 - \sqrt 2 }} - \dfrac{6}{{\sqrt 3 }}\\
= \dfrac{{7\left( {\sqrt {10} + \sqrt 3 } \right)}}{{10 - 3}} - \dfrac{{\sqrt {10} \left( {\sqrt 5 - \sqrt 2 } \right)}}{{\sqrt 5 - \sqrt 2 }} - 2\sqrt 3 \\
= \sqrt {10} + \sqrt 3 - \sqrt {10} - 2\sqrt 3 \\
= - \sqrt 3
\end{array}$
