Решение:

1. a) $$rac{m}{\sqrt{x}} = \frac{m \cdot \sqrt{x}}{\sqrt{x} \cdot \sqrt{x}} = \frac{m\sqrt{x}}{x}$$

2. б) $$rac{1}{\sqrt{2}} = \frac{1 \cdot \sqrt{2}}{\sqrt{2} \cdot \sqrt{2}} = \frac{\sqrt{2}}{2}$$

3. в) $$rac{3}{5\sqrt{c}} = \frac{3 \cdot \sqrt{c}}{5\sqrt{c} \cdot \sqrt{c}} = \frac{3\sqrt{c}}{5c}$$

4. г) $$rac{a}{2\sqrt{3}} = \frac{a \cdot \sqrt{3}}{2\sqrt{3} \cdot \sqrt{3}} = \frac{a\sqrt{3}}{2 \cdot 3} = \frac{a\sqrt{3}}{6}$$

5. д) $$rac{3}{2\sqrt{3}} = \frac{3 \cdot \sqrt{3}}{2\sqrt{3} \cdot \sqrt{3}} = \frac{3\sqrt{3}}{2 \cdot 3} = \frac{3\sqrt{3}}{6} = \frac{\sqrt{3}}{2}$$

6. e) $$\frac{5}{4\sqrt{15}} = \frac{5 \cdot \sqrt{15}}{4\sqrt{15} \cdot \sqrt{15}} = \frac{5\sqrt{15}}{4 \cdot 15} = \frac{5\sqrt{15}}{60} = \frac{\sqrt{15}}{12}$$