Упростите выражение:
1) $\frac{\sqrt{x}}{\sqrt{x} - 3} - \frac{x}{x - 9}$;
2) $(\frac{\sqrt{b}}{\sqrt{b} - \sqrt{c}} + \frac{\sqrt{b}}{\sqrt{c}}) : \frac{\sqrt{b}}{\sqrt{b} - \sqrt{c}}$.
$\frac{\sqrt{x}}{\sqrt{x} - 3} - \frac{x}{x - 9} = \frac{\sqrt{x}}{\sqrt{x} - 3} - \frac{x}{(\sqrt{x} - 3)(\sqrt{x} + 3)} = \frac{\sqrt{x}(\sqrt{x} + 3) - x}{(\sqrt{x} - 3)(\sqrt{x} + 3)} = \frac{x + 3\sqrt{x} - x}{x - 9} = \frac{3\sqrt{x}}{x - 9}$
$(\frac{\sqrt{b}}{\sqrt{b} - \sqrt{c}} + \frac{\sqrt{b}}{\sqrt{c}}) : \frac{\sqrt{b}}{\sqrt{b} - \sqrt{c}} = \frac{\sqrt{b} * \sqrt{c} + \sqrt{b}(\sqrt{b} - \sqrt{c})}{\sqrt{c}(\sqrt{b} - \sqrt{c})} * \frac{\sqrt{b} - \sqrt{c}}{\sqrt{b}} = \frac{\sqrt{bc} + b - \sqrt{bc}}{\sqrt{c}} * \frac{1}{\sqrt{b}} = \frac{b}{\sqrt{bc}} = \frac{\sqrt{b}}{\sqrt{c}} = \sqrt{\frac{b}{c}}$
Пожауйста, оцените решение
