#### Answer

$4\sqrt{3}$

#### Work Step by Step

Simplify each radical to obtain:
$=\sqrt{3} +\sqrt{27}
\\=\sqrt{3} +\sqrt{9(3)}
\\=\sqrt{3}+\sqrt{3^2(3)}
\\=\sqrt{3} + 3\sqrt{3}$
RECALL:
The distributive property states that for any real numbers a, b, and c:
(1) $ac + bc = (a+b)c$
(2) $ac-bc=(a-b)c$
Use rule (1) above to combine like terms and obtain:
$=(1+3)\sqrt{3}
\\=4\sqrt{3}$