\[\boxed{\mathbf{632\ (632).\ }Еуроки\ - \ ДЗ\ без\ мороки}\]
\[x^{2} - 4x + 1 = 0\]
\[x = 2 - \sqrt{3};\ \ x = 2 + \sqrt{3} \Longrightarrow\]
\[\Longrightarrow корни\ уравнения:\]
\[Что\ и\ требовалось\ доказать.\]
\[\boxed{\mathbf{63}\mathbf{2}\mathbf{\text{.\ }}Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ \sqrt{\left( 1 - \sqrt{2} \right)^{2}} = \left| 1 - \sqrt{2} \right| =\]
\[= - 1 + \sqrt{2}\]
\[2)\ \sqrt{\left( \sqrt{6} - \sqrt{7} \right)^{2}} = \left| \sqrt{6} - \sqrt{7} \right| =\]
\[= \sqrt{7} - \sqrt{6}\]
\[3)\ \sqrt{\left( 2\sqrt{5} - 3 \right)^{2}} = 2\sqrt{5} - 3\]
\[4)\ \sqrt{\left( \sqrt{3} - 2 \right)^{2}} + \sqrt{\left( 3 - \sqrt{3} \right)^{2}} =\]
\[= \left| \sqrt{3} - 2 \right| + \left| 3 - \sqrt{3} \right| =\]
\[= 2 - \sqrt{3} + 3 - \sqrt{3} = 5 - 2\sqrt{3}\]