| $$ \begin{aligned}10+3i+3-7i& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-4i+13\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{10} + \color{red}{3i} + \color{blue}{3} \color{red}{-7i} = \color{red}{-4i} + \color{blue}{13} $$ |