\[\left( \frac{\sqrt{2}}{x} + \frac{\sqrt{2}}{y} \right)\ :\frac{\sqrt{5}}{x - y} =\]
\[= \frac{\sqrt{2}(x + y)(x - y)}{\text{xy} \cdot \sqrt{5}} =\]
\[= \frac{\sqrt{2}\left( x^{2} - y^{2} \right)}{\sqrt{5}\text{xy}}\]
\[x = \sqrt[4]{12 - 2\sqrt{35}};\ \ \ \]
\[y = \sqrt[4]{12 + 2\sqrt{35}}:\]
\[= \sqrt{12 - 2\sqrt{35}} - \sqrt{12 + 2\sqrt{35}} =\]
\[xy =\]
\[= \sqrt[4]{12 - 2\sqrt{35}} \cdot \sqrt[4]{12 + 2\sqrt{35}} =\]
\[= \sqrt[4]{\left( 12 - 2\sqrt{35} \right)\left( 12 + 2\sqrt{35} \right)} =\]
\[= \sqrt[4]{\left( \sqrt{5} - \sqrt{7} \right)^{2}\left( \sqrt{5} + \sqrt{7} \right)^{2}} =\]
\[= \sqrt[4]{\left( \left( \sqrt{5} - \sqrt{7} \right)\left( \sqrt{5} + \sqrt{7} \right) \right)^{2}} =\]
\[= \sqrt[4]{\left( \left( \sqrt{5} \right)^{2} - \left( \sqrt{7} \right)^{2} \right)} =\]
\[= \sqrt[4]{(5 - 7)^{2}} = \sqrt[4]{( - 2)^{2}} = \sqrt{2}\]
\[\frac{\sqrt{2}\left( x^{2} - y^{2} \right)}{\sqrt{5}\text{xy}} = \frac{\sqrt{2} \cdot \left( - 2\sqrt{5} \right)}{\sqrt{5} \cdot \sqrt{2}} =\]
\[= - \frac{2 \cdot \sqrt{5} \cdot \sqrt{2}}{\sqrt{5} \cdot \sqrt{2}} = - 2.\]