Question 323154
{{{3i(2+5i)=x+6i}}} First distribute 3i to remove parenthesis
{{{6i+15i^2=x+6i}}} because  {{{i=sqrt(-1), {{{i^2=-1}}} replace {{{i^2}}} with -1
{{{6i+15(-1)=x+6i}}} now solve for x
{{{6i-6i-15=x}}} 
{{{-15=x}}}