Question
Answer
$$(11+9i)\cdot(11+9i)=81i^2+198i+121$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}(11+9i)\cdot(11+9i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}121+99i+99i+81i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}81i^2+198i+121\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{11+9i}\right) $ by each term in $ \left( 11+9i\right) $. $$ \left( \color{blue}{11+9i}\right) \cdot \left( 11+9i\right) = 121+99i+99i+81i^2 $$ |
| ② | Combine like terms: $$ 121+ \color{blue}{99i} + \color{blue}{99i} +81i^2 = 81i^2+ \color{blue}{198i} +121 $$ |
This page was created using
Complex Expression calculator