| $$ \begin{aligned}1-2i+4+5i& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}3i+5\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{1} \color{red}{-2i} + \color{blue}{4} + \color{red}{5i} = \color{red}{3i} + \color{blue}{5} $$ |