Question

if x=9+4√5 then find √x-1/√x

Answer 1

$\sqrt{x} = \sqrt{4 + 5 + 4 \sqrt{5 } } = 2 + \sqrt{5}$
$1 \div \sqrt{x} = 2 - \sqrt{5}$
(2 + √5) - ( 2-√5) = 2√5 and 2+√5 +2-√5 = 4