Question 1137576
{{{ (-4 sqrt(51))*(6sqrt(3))  }}}<br>

Combine the -4 and 6, and bring the 51 and 3 together under the sqrt sign:
 = {{{-24 * sqrt(51*3) }}}<br>

 = {{{-24 * sqrt(3*17*3) }}}<br>
= {{{ -24 * 3 * sqrt(17) }}}<br>
=  {{{ highlight(-72*sqrt(17)) }}}