Question

Очень нужно! 
${{1}over{2+sqrt{3}}}+{{1}over{sqrt{3}+sqrt{2}}}+{{1 }over{sqrt{2}-1}}$

Answer 1

$frac{1}{2+sqrt{3}} = 2-sqrt{3}\ frac{1}{sqrt{3}+sqrt{2}}=sqrt{3}-sqrt{2}\ frac{1}{sqrt{2}-1}=sqrt{2}+1\ \ 2-sqrt{3}+sqrt{3}-sqrt{2}+sqrt{2}+1 = 3$