Answer
$13+20i$
Work Step by Step
Removing the grouping symbols, the given expression, $
(3+11i)+(10+9i)
,$ is equivalent to
\begin{align*}
&
3+11i+10+9i
\\&=
(3+10)+(11i+9i)
&\text{ (combine like terms)}
\\&=
13+(20i)
\\&=
13+20i
.\end{align*}
Hence, the given expression simplifies to $
13+20i
$.
