\[\boxed{\mathbf{541\ (541).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ \left( 3 + \sqrt{5} \right)^{2} - 6\sqrt{5} =\]
\[= 9 + 6\sqrt{5} + 5 - 6\sqrt{5} = 14;\]
\[2)\ \left( \sqrt{12} - 2\sqrt{2} \right)^{2} + 8\sqrt{6} =\]
\[= 12 - 4\sqrt{24} + 8 + 8\sqrt{6} =\]
\[= 12 - 8\sqrt{6} + 8 + 8\sqrt{6} = 20\]
\[\boxed{\mathbf{5}\mathbf{4}\mathbf{1}\mathbf{\text{.\ }}Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ \sqrt{a^{10}} = a^{5},\ \ при\ a \geq 0;\]
\[2)\ \sqrt{a^{10}} = - a^{5},\ \ при\ a < 0;\]
\[3)\ \sqrt{a^{2}} = \left( \sqrt{a} \right)^{2},\ \ для\ a \geq 0;\]
\[4)\ \sqrt{a^{2}} = \left( \sqrt{- a} \right)^{2},\ \ \]
\[при\ a < 0.\]