[latex]( \sqrt{6- \sqrt{11}} - \sqrt{6+ \sqrt{11} })^{2} * \frac{2}{3}^{-1} [/latex]

[latex] (\sqrt{6- \sqrt{11} }- \sqrt{6+ \sqrt{11} }) ^{2} \cdot (\frac{2}{3}) ^{-1}= \\= (6- \sqrt{11}-2 \sqrt{ ({6- \sqrt{11} )({6+ \sqrt{11}) }}}+6+ \sqrt{11})\cdot \frac{3}{2}= \\ = (12-2 \sqrt{ {6 ^{2} - (\sqrt{11} ) ^{2} }}}\cdot \frac{3}{2}= \\ =(12-2 \sqrt{25})\cdot \frac{3}{2}=(12-10)\cdot \frac{3}{2}=3 [/latex]