Z1=-2-4i z2=3+6i z3=1-8i z4=-7-3i L1=-2 L2=5
a) L1z1+L2z2=-2(-2-4i)+5(3+6i)=4+8i+15+30i=19+38i
b) z1z2=(-2-4i)(3+6i)=-6-12i-12i+24=18-24i
c) z3z4=(1-8i)(-7-3i)=-7+56i-3i-24=-31+53i
d) 1/z2=1/(3+6i)=(3-6i)/[(3+6i)(3-6i)]=(3-6i)/(9+36)=(3-6i)/45=1/15 - 2/15 i
e) z4/z1 = (-7-3i)/(-2-4i)=[(-7-3i)(-2+4i)/[(-2-4i)(-2+4i)]=(26-22i)/20=1,3-1,1i
f) z1/z3=(-2-4i)/(1-8i)=[(-2-4i)(1+8i)]/[(1-8i)(1+8i)]=(30-20i)/65=6/13 - 4/13 i