#### Answer

$3(x+4)\times\sqrt{10(x+4)}$

#### Work Step by Step

$\sqrt{90(x+4)^3}$
Factor out perfect squares.
$\sqrt{9\times 10\times(x+4)^2\times(x+4)}$
Use the Product Property of Square Roots.
$\sqrt9\times\sqrt{10}\times\sqrt{(x+4)^2}\times\sqrt{x+4}$
Simplify.
$3\times\sqrt{10}\times(x+4)\times\sqrt{x+4}$
Use the Product Property of Square Roots.
$3(x+4)\times\sqrt{10(x+4)}$