Question
Answer
$$(-1-7i)\cdot(-2+6i)=-42i^2+8i+2$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}(-1-7i)\cdot(-2+6i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}2-6i+14i-42i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-42i^2+8i+2\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{-1-7i}\right) $ by each term in $ \left( -2+6i\right) $. $$ \left( \color{blue}{-1-7i}\right) \cdot \left( -2+6i\right) = 2-6i+14i-42i^2 $$ |
| ② | Combine like terms: $$ 2 \color{blue}{-6i} + \color{blue}{14i} -42i^2 = -42i^2+ \color{blue}{8i} +2 $$ |
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