Question 596411
108 has a perfect square as a factor

108 = 36 * 3

so {{{sqrt(-108)}}} = {{{sqrt(108)*sqrt(-1)}}} = {{{i*sqrt(36*3)}}} = {{{i*sqrt(36)*sqrt(3)}}} = {{{6i*sqrt(3)}}}
<p>

{{{(6 +- 6i*sqrt(3))/2}}}

<p>

3 +- 3i*sqrt(3)