Question
Answer
$$(2+3i)\cdot(4-i)=-3i^2+10i+8$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}(2+3i)\cdot(4-i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}8-2i+12i-3i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-3i^2+10i+8\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{2+3i}\right) $ by each term in $ \left( 4-i\right) $. $$ \left( \color{blue}{2+3i}\right) \cdot \left( 4-i\right) = 8-2i+12i-3i^2 $$ |
| ② | Combine like terms: $$ 8 \color{blue}{-2i} + \color{blue}{12i} -3i^2 = -3i^2+ \color{blue}{10i} +8 $$ |
This page was created using
Complex Expression calculator