Tap the blue circles to see an explanation.
$$ \begin{aligned}(11+i)\cdot(4-4i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}44-44i+4i-4i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}-4i^2-40i+44\end{aligned} $$ | |
① | Multiply each term of $ \left( \color{blue}{11+i}\right) $ by each term in $ \left( 4-4i\right) $. $$ \left( \color{blue}{11+i}\right) \cdot \left( 4-4i\right) = 44-44i+4i-4i^2 $$ |
② | Combine like terms: $$ 44 \color{blue}{-44i} + \color{blue}{4i} -4i^2 = -4i^2 \color{blue}{-40i} +44 $$ |