Answer
$5 + 12i$
Work Step by Step
RECALL:
(1) $(a+b)^2 = a^2+ 2ab + b^2$
(2) $i^2=-1$
Use rule (1) above with $a=3$ and $b=2i$ to obtain:
$=3^2 +2(3)(2i) + (2i)^2
\\=9 +12i + 4i^2$
Use rule (2) above to obtain:
$=9 +12i + 4(-1)
\\=9+12i+(-4)
\\=5 + 12i$
