Question

Один пример по алгебре 7 класс.
$\frac{5}{ \sqrt{13} + \sqrt{3} }$
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Answer 1

$\tt\displaystyle \frac{5}{\sqrt{13}+\sqrt{3}}=\frac{5*(\sqrt{13}-\sqrt{3})}{(\sqrt{13}+\sqrt{3})(\sqrt{13}-\sqrt{3})}=\\\\\\=\frac{5*(\sqrt{13}-\sqrt{3})}{13-3}=\frac{5*(\sqrt{13}-\sqrt{3})}{10}=\\\\\\=\frac{\sqrt{13}-\sqrt{3}}{2}$