Question 479289
<br>
{{{sqrt(864x^2)}}} = {{{sqrt(864)*sqrt(x^2)}}}<br>
You have correctly that {{{sqrt(864)=12*sqrt(6)}}}.<br>
For simplifying {{{sqrt(x^2)}}}, note that x can be positive or negative (or zero), but {{{sqrt(A)}}} is always non-negative.  So<br>
{{{sqrt(x^2)}}} = {{{abs(x)}}}<br>
ANSWER: {{{sqrt(864x^2)}}} = {{{12*sqrt(6)*abs(x)}}}<br>