Answer
$7\sqrt{3}$
Work Step by Step
Simplify each radical to have
$5\sqrt3+\sqrt{4(3)} \text{ and}
\\5\sqrt{3} + 2\sqrt{3}.$
RECALL:
$ac+bc=(a+b)c$
Combine like terms using the rule above to have:
$=(5+2)\sqrt{3}
\\=7\sqrt{3}.$