# Can we write sqrt(9+4) as sqrt9 + sqrt4? Justify?

Aug 5, 2017

$s = \sqrt{9 + 4}$ if and only if ${s}^{2} = 9 + 4 = 13$
$\sqrt{9} + \sqrt{4} = 3 + 2 = 5$ and ${5}^{2} \ne 13$
So $5 \ne \sqrt{9 + 4}$