Tap the blue circles to see an explanation.
$$ \begin{aligned}(-6-6i)\cdot(-5-5i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}30+30i+30i+30i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}30i^2+60i+30\end{aligned} $$ | |
① | Multiply each term of $ \left( \color{blue}{-6-6i}\right) $ by each term in $ \left( -5-5i\right) $. $$ \left( \color{blue}{-6-6i}\right) \cdot \left( -5-5i\right) = 30+30i+30i+30i^2 $$ |
② | Combine like terms: $$ 30+ \color{blue}{30i} + \color{blue}{30i} +30i^2 = 30i^2+ \color{blue}{60i} +30 $$ |