Answer
$2+11i$
Work Step by Step
Multiply each term of the first complex number by each term of the second, then combine like terms and use the fact that $i^2=-1$to obtain:
$$
(3+4i)(2+i)=3(2+1)+4i(2+i)
\\=6+3i+8i+4i^2
\\=6+11i+4(-1)
\\=6+11i-4
\\=2+11i
$$
