#### Answer

72

#### Work Step by Step

First of all, in order to make this one large square root, we multiply the coefficients to obtain that the new coefficient is 12. Also, recall, $\sqrt{a}\times \sqrt{b}= \sqrt{a \times b}$. Thus, we can multiply 6 and 6 to obtain the simplified expression:
$12\sqrt{6 \times 6}=12\sqrt{36}=72$