Multiply $( 3 + 8 i ) ( 2 - 13 i )$ and write in standard form.
A) $- 110 + 23 i$
B) $23 + 110 i$
C) $- 110 - 23 i$
D) $110 - 23 i$
E) $- 23 - 23 i$

Question

Quizplus · Accepted Answer

Apply the distributive property and use the fact that $i^2=-1$.
\begin{align*}
( 3 + 8 i ) ( 2 - 13 i ) &= 3(2) - 3(13i) + 8i(2) - 8i(13i)\
&= 6 - 39i + 16i + 104\
&=110 - 23i
\end{align*}
Therefore, the answer is choice D.

Multiply (3+8i)(2−13i)( 3 + 8 i ) ( 2 - 13 i )(3+8i)(2−13i)

Multiply $( 3 + 8 i ) ( 2 - 13 i )$