Question

Сократительной дробь.
(скоротiть дрiб) (8-9 класс)
1) √х+11
--------
х-121

2) 15+√15
---------
√15

3) 5-√10
--------
√10-2

Answer 1

$\frac{\sqrt{x} + 11}{x - 121} = \frac{\sqrt{x} + 11}{(\sqrt x + 11)(\sqrt x - 11)} = \frac{1}{\sqrt x - 11} \\ \\ \frac{15 + \sqrt {15}} {\sqrt {15}} = \frac{\sqrt {15} (\sqrt {15} + 1)} {\sqrt {15}} = \sqrt {15} + 1 \\ \\ \frac{5 - \sqrt{10}}{\sqrt {10} - 2} = \frac{\sqrt5(\sqrt5 - \sqrt2)}{\sqrt2(\sqrt{5} - \sqrt{2})} = \sqrt{\frac 5 2}$