Z₁=8+3i ; z₂=6-3i найти:
z₁+z₂ = 8 + 3i + 6 -3i = 14
;z₁-z₂ = ( 8 + 3i) - ( 6 - 3i ) = 8 + 3i - 6 + 3i = 2 + 6i
z₁*z₂= ( 8 + 3i) *( 6 - 3i ) = 48 +18i -24i -9i² = 57 - 6i
z₁/z₂ = ( 8 + 3i) /( 6 - 3i ) = ( 8 + 3i) *( 6 + 3i ) / ( 6 - 3i) *( 6 + 3i ) =
=(48 + 42i + 9i²)/(36 - 9i²) = (39+42i)/45= (13 + 14i)/5
(надо учесть, что i² = -1)