Question
Answer
$$(-3+7i)\cdot(9+8i)=56i^2+39i-27$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}(-3+7i)\cdot(9+8i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-27-24i+63i+56i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}56i^2+39i-27\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{-3+7i}\right) $ by each term in $ \left( 9+8i\right) $. $$ \left( \color{blue}{-3+7i}\right) \cdot \left( 9+8i\right) = -27-24i+63i+56i^2 $$ |
| ② | Combine like terms: $$ -27 \color{blue}{-24i} + \color{blue}{63i} +56i^2 = 56i^2+ \color{blue}{39i} -27 $$ |
This page was created using
Complex Expression calculator