Question
Answer
$$(-5-6i)\cdot(-8-7i)=42i^2+83i+40$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}(-5-6i)\cdot(-8-7i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}40+35i+48i+42i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}42i^2+83i+40\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{-5-6i}\right) $ by each term in $ \left( -8-7i\right) $. $$ \left( \color{blue}{-5-6i}\right) \cdot \left( -8-7i\right) = 40+35i+48i+42i^2 $$ |
| ② | Combine like terms: $$ 40+ \color{blue}{35i} + \color{blue}{48i} +42i^2 = 42i^2+ \color{blue}{83i} +40 $$ |
This page was created using
Complex Expression calculator