Question

Номер 81. Плиз СРОЧНО!!!

Answer 1

$\frac{a - 3}{ \sqrt{a} - \sqrt{3} } = \frac{(\sqrt{a} + \sqrt{3}) (\sqrt{a} - \sqrt{3} )}{\sqrt{a} - \sqrt{3}} = \\ = \sqrt{a} + \sqrt{3}$
$\frac{2x - 5}{ \sqrt{2x} + \sqrt{5} } = \frac{(\sqrt{2x} + \sqrt{5}) (\sqrt{2x} - \sqrt{5}) }{\sqrt{2x} + \sqrt{5} } = \sqrt{2x} - \sqrt{5}$
$\frac{a - b}{ \sqrt{a} - \sqrt{b} } = \frac{(\sqrt{a} - \sqrt{b})(\sqrt{a} + \sqrt{b})}{\sqrt{a} - \sqrt{b}} = \sqrt{a} + \sqrt{b}$