\[\boxed{\text{504\ (504).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[Чтобы\ избавиться\ от\ \]
\[иррациональности,\ домножим\ \]
\[дробь\ на\ корень\]
\[(знаменатель\ выражения).\]
\[\textbf{а)}\ \frac{1 + \sqrt{a}}{\sqrt{a}} = \frac{\left( 1 + \sqrt{a} \right) \cdot \sqrt{a}}{\sqrt{a} \cdot \sqrt{a}} =\]
\[= \frac{\sqrt{a} + a}{a}\]
\[\textbf{б)}\ \frac{y - b\sqrt{y}}{b\sqrt{y}} = \frac{\left( y + b\sqrt{y} \right) \cdot \sqrt{y}}{b\sqrt{y} \cdot \sqrt{y}\ } =\]
\[= \frac{y\sqrt{y} + by}{\text{by}} = \frac{y \cdot \left( \sqrt{y} + b \right)}{\text{by}} =\]
\[= \frac{\sqrt{y} + b}{b}\ \]
\[\textbf{в)}\ \frac{x - \sqrt{\text{ax}}}{a\sqrt{x}} = \frac{\sqrt{x} \cdot \left( \sqrt{x} - \sqrt{a} \right)}{a\sqrt{x}} =\]
\[= \frac{\sqrt{x} - \sqrt{a}}{a}\ \]
\[\textbf{г)}\frac{\text{\ a}\sqrt{b} + b\sqrt{a}\ }{\sqrt{\text{ab}}} =\]
\[= \frac{\sqrt{a}\sqrt{b} \cdot \left( \sqrt{a} + \sqrt{b} \right)}{\sqrt{\text{ab}}} = \sqrt{a} + \sqrt{b}\]
\[\textbf{д)}\ \frac{2\sqrt{3} - 3}{5\sqrt{3}} = \frac{\sqrt{3} \cdot \left( 2 - \sqrt{3} \right)}{5\sqrt{3}} =\]
\[= \frac{2 - \sqrt{3}}{5}\ \]
\[\textbf{е)}\ \frac{2 - 3\sqrt{2}}{4\sqrt{2}} = \frac{\sqrt{2} \cdot \left( \sqrt{2} - 3 \right)}{4\sqrt{2}} =\]
\[= \frac{\sqrt{2} - 3}{4}\ \]

