Question

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

2) 15+√15
---------
√15

3) 5-√10
--------
√10-2

Answer 1

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