\[\boxed{\text{886}\text{\ (886)}\text{.}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[\textbf{а)}\ 3x^{2} - 6x - 5\ \ \ \ \]
\[при\ x = 1 + \sqrt{2}:\]
\[3x^{2} - 6x - 5 =\]
\[= 3 \cdot \left( 1 + \sqrt{2} \right)^{2} - 6 \cdot \left( 1 + \sqrt{2} \right) - 5 =\]
\[= 3 + 6\sqrt{2} + 6 - 6 - 6\sqrt{2} - 5 =\]
\[= - 2.\]
\[\textbf{б)}\ \frac{x^{2} - x - 5}{x - 1}\]
\[при\ x = \sqrt{5} + 1:\]
\[\frac{x^{2} - x - 5}{x - 1} =\]
\[= \frac{\left( \sqrt{5} + 1 \right)^{2} - \left( \sqrt{5} + 1 \right) - 5}{\sqrt{5} + 1 - 1} =\]
\[= \frac{5 + 2\sqrt{5} + 1 - \sqrt{5} - 1 - 5}{\sqrt{5}} =\]
\[= \frac{\sqrt{5}}{\sqrt{5}} = 1.\]