Answer
$$9+5i\cdot9-5i=40i+9$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}9+5i\cdot9-5i& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}9+45i-5i \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}40i+9\end{aligned} $$ | |
| ① | $$ 5 i \cdot 9 = 45 i $$ |
| ② | Combine like terms: $$ 9+ \color{blue}{45i} \color{blue}{-5i} = \color{blue}{40i} +9 $$ |
This page was created using
Complex Expression calculator