\[\boxed{\mathbf{856\ (856).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[\frac{144}{\left( a^{2} - 36 \right)^{2}} = \frac{144}{\left( a^{2} - 36 \right)^{2}}.\]
\[\frac{(a - b)(a - c)(c - b)}{(a - b)(a - c)(c - b)} = 1\]
\[1 = 1.\]
\[\boxed{\mathbf{8}\mathbf{5}\mathbf{6}\mathbf{\text{.\ }}Еуроки\ - \ ДЗ\ без\ мороки}\]
\[a^{2} - 2\sqrt{5}a + 2 =\]
\[= \left( a - \sqrt{5} \right)^{2} - 3 =\]
\[= \left( a - \sqrt{5} - \sqrt{3} \right)\left( a - \sqrt{5} + \sqrt{3} \right)\]
\[при\ a = \sqrt{5} - 3:\ \]
\[= - \left( 3 + \sqrt{3} \right)\left( \sqrt{3} - 3 \right) =\]
\[= - ( - 9 + 3) = 6\]
\[Ответ:6.\]