Question
Answer
$$(-7-6i)\cdot(2-i)=6i^2-5i-14$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}(-7-6i)\cdot(2-i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-14+7i-12i+6i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}6i^2-5i-14\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{-7-6i}\right) $ by each term in $ \left( 2-i\right) $. $$ \left( \color{blue}{-7-6i}\right) \cdot \left( 2-i\right) = -14+7i-12i+6i^2 $$ |
| ② | Combine like terms: $$ -14+ \color{blue}{7i} \color{blue}{-12i} +6i^2 = 6i^2 \color{blue}{-5i} -14 $$ |
This page was created using
Complex Expression calculator