Question

Calculati:
$\sqrt{4- \sqrt{7}}$ · $\sqrt{4+ \sqrt{7}}$

Answer 1

$\sqrt{4- \sqrt{7} *4 + \sqrt7} } . Folosind (a-b)(a+b) = a*a - b*b -\ \textgreater \ \sqrt{ 4^{2} - 7}$ = $\sqrt{9} = 3$