How do I solve this operation

How Do I Solve This Operation class=

Sagot :

4 / ( 3 + 5i ) = [ 4( 3 - 5i)] / [ 3^2 - (5i)^2 ] = [ 4( 3 - 5i)] / 34 =  [ 2( 3 - 5i)] / 17 =
 6 / 17 - 10i / 17;