Question
Answer
$$(6+9i)\cdot(6+9i)=81i^2+108i+36$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}(6+9i)\cdot(6+9i)& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}36+54i+54i+81i^2 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}81i^2+108i+36\end{aligned} $$ | |
| ① | Multiply each term of $ \left( \color{blue}{6+9i}\right) $ by each term in $ \left( 6+9i\right) $. $$ \left( \color{blue}{6+9i}\right) \cdot \left( 6+9i\right) = 36+54i+54i+81i^2 $$ |
| ② | Combine like terms: $$ 36+ \color{blue}{54i} + \color{blue}{54i} +81i^2 = 81i^2+ \color{blue}{108i} +36 $$ |
This page was created using
Complex Expression calculator