#### Answer

$\color{blue}{-\dfrac{4}{3}\sqrt{3}}$

#### Work Step by Step

Bring out the square root of $16$, which is 4, to obtain:
$=-4\sqrt{\dfrac{1}{3}}$
Rationalize the denominator by multiplying $3$ to both the numerator and the denominator of the radicand to obtain:
$=-4\sqrt{\dfrac{1(3)}{3(3)}}
\\=-4\sqrt{\dfrac{3}{3^2}}$
Bring out the square root of the denominator to obtain:
$=\color{blue}{-\dfrac{4}{3}\sqrt{3}}$