Solution - Basic complex operations

Complex Division

Determine the conjugate of the denominator :
The conjugate of  ( 2 +  4i)  is  ( 2 -  4i) 

Multiply the numerator and denominator by the conjugate:
 ( 4 + i)•( 2 -  4i) = ( 12 -  14i)
( 2 +  4i)•( 2 -  4i) = ( 20 +  0i) = 20 
Note:
(1) Multiplying both the numerator and the denominator by the same number does not change the value of the fraction.
(2) The new denominator is a real number as its imaginary part is zero.

 ( 4 + i)/( 2 +  4i) =
  0.0500 • ( 12 -  14i)