Answer
$$(-1+2i)\cdot(3+4i)=8i^2+2i-3$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}(-1+2i)\cdot(3+4i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-3-4i+6i+8i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}8i^2+2i-3\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{-1+2i}\right) $ by each term in $ \left( 3+4i\right) $. $$ \left( \color{blue}{-1+2i}\right) \cdot \left( 3+4i\right) = -3-4i+6i+8i^2 $$ |
| ② | Combine like terms: $$ -3 \color{blue}{-4i} + \color{blue}{6i} +8i^2 = 8i^2+ \color{blue}{2i} -3 $$ |
This page was created using
Complex Expression calculator