Question

Решите.√18-(√14-2√7)*√7

Answer 1

$\sqrt{18}-(\sqrt{14}-2 \sqrt{7})* \sqrt{7}=\sqrt{9*2}-(\sqrt{14*7}-2 \sqrt{7*7})= \\ =3\sqrt{2}-(7\sqrt{2}-2*7)=3\sqrt{2}-7\sqrt{2}+14=14-4 \sqrt{2}$