Question 404515
{{{(6-i)/(6+3i)}}} Multiply numerator and denominator of fraction at {{{(6-3i)}}}
{{{((6-i)*(6-3i))/((6+3i)*(6-3i))}}} 
Use formulas {{{(a-b)(a+b)=a^2-b^2}}}
___________{{{i^2=-1}}}
{{{((6-i)*(6-3i))/((6+3i)*(6-3i))=(6*6-6*3i-i*6+i*3i)/(6^2-(3i)^2)=(36-18i-6i-3)/(36-9*(-1))=(33-24i)/45=(3(11-8i))/45=(11-8i)/15}}}