Tap the blue circles to see an explanation.
$$ \begin{aligned}(12-2i)\cdot(3-4i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}36-48i-6i+8i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}8i^2-54i+36\end{aligned} $$ | |
① | Multiply each term of $ \left( \color{blue}{12-2i}\right) $ by each term in $ \left( 3-4i\right) $. $$ \left( \color{blue}{12-2i}\right) \cdot \left( 3-4i\right) = 36-48i-6i+8i^2 $$ |
② | Combine like terms: $$ 36 \color{blue}{-48i} \color{blue}{-6i} +8i^2 = 8i^2 \color{blue}{-54i} +36 $$ |