2/(√(2x+y)-√(2x-y)).
\[\frac{2}{\sqrt{2x + y} - \sqrt{2x - y}} =\]
\[= \frac{2 \cdot \left( \sqrt{2x + y} + \sqrt{2x - y} \right)}{\left( \sqrt{2x + y} - \sqrt{2x - y} \right)\left( \sqrt{2x + y} + \sqrt{2x - y} \right)} =\]
\[= \frac{2 \cdot \left( \sqrt{2x + y} + \sqrt{2x - y} \right)}{2x + y - (2x - y)} =\]
\[= \frac{2 \cdot \left( \sqrt{2x + y} + \sqrt{2x - y} \right)}{2x + y - 2x + y} =\]
\[= \frac{2 \cdot \left( \sqrt{2x + y} + \sqrt{2x - y} \right)}{2y} =\]
\[= \frac{\sqrt{2x + y} + \sqrt{2x - y}}{y}\]