Question

(3) / (корень из 2 - 1)- корень из 18

Answer 1

$frac{3}{sqrt2-1}-sqrt{18}=frac{3-sqrt{18}(sqrt2-1)}{sqrt2-1}= frac{3-sqrt{36}+sqrt{18}}{sqrt2-1}=frac{sqrt{18}-3}{sqrt2-1}=frac{3sqrt2-3}{sqrt2-1}= \ \ =frac{3(sqrt2-1)}{sqrt2-1}=3$