Question 244809
(3+4i)(1-2i)
remember that i=sqrt(-1)and that i^2=-1
use foil
first term 3*1=3
outer terms 3*2i=6i
inner terms 1*4i=4i
add (6+4)(i)=10i

last terms 4i*2i=8(-1)=-8
3+10i-8
10i-5