z1+z2=0,2+4i -0,3-0,9i=0.2-0.3+4i-0.9i=-0.1+3.1i
z1*z2=(0,2+4i) *(-0,3-0,9i)=0.2*(-0.3)-0.2*0.9i+4i*(-0.3)+4i*(-0.9i)=-0.06-0.18i-1.2i+3.6=3.54-1.38i
z1+z2=0,2+4i -0,3-0,9i=0.2-0.3+4i-0.9i=-0.1+3.1i
z1*z2=(0,2+4i) *(-0,3-0,9i)=0.2*(-0.3)-0.2*0.9i+4i*(-0.3)+4i*(-0.9i)=-0.06-0.18i-1.2i+3.6=3.54-1.38i