Question

а)
$\frac{7}{2 \sqrt{21} }$
б)
$\frac{22}{ \sqrt{13} - \sqrt{2} }$
​

Answer 1

Ответ:

$\dfrac{7}{2\sqrt{21}}=\dfrac{7\sqrt{21}}{2\cdot 21}=\dfrac{7\sqrt{21}}{42}=\dfrac{\sqrt{21}}{6}\\\\\\\dfrac{22}{\sqrt{13}-\sqrt2}=\dfrac{22\cdot (\sqrt{13}+\sqrt2)}{ (\sqrt{13}-\sqrt2) (\sqrt{13}+\sqrt2)}=\dfrac{22\cdot (\sqrt{13}+\sqrt2)}{13-2}=2\cdot (\sqrt{13}+\sqrt2)$