Question

Освободите от знака корня в знаменателе
7/2√21=
22/√13-√2=

Answer 1

$frac{7}{2 sqrt{21} } = frac{7sqrt{21} }{2 sqrt{21}*sqrt{21} } = frac{7sqrt{21} }{2*21}= frac{7sqrt{21} }{42} = frac{sqrt{21} }{6} \ \ frac{22}{sqrt{13}-sqrt{2} } = frac{22(sqrt{13}+sqrt{2})}{(sqrt{13}-sqrt{2})(sqrt{13}+sqrt{2})} = frac{22(sqrt{13}+sqrt{2})}{13-2} = \ = frac{22(sqrt{13}+sqrt{2})}{11}=2(sqrt{13}+sqrt{2})=2 sqrt{13}+2 sqrt{2}$

Answer 2

спасиб