3 - 3i
--------
3 + 8i
(3 - 3i)(3 - 8i)
------------------ {multiplied top and bottom by conjugate of denominator}
(3 + 8i)(3 + 8i)
9 - 33i - 24i²
----------------- {used foil method on top and bottom}
9 - 64i²
9 - 33i - 24(-1)
-------------------- {in imaginary numbers, i² is -1}
9 - 64(-1)
9 - 33i + 24
----------------- {simplified}
9 + 64
33 - 33i
-------------- {combined like terms on top and bottom}
73