| $$ \begin{aligned}3+7i-2-3i& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}4i+1\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{3} + \color{red}{7i} \color{blue}{-2} \color{red}{-3i} = \color{red}{4i} + \color{blue}{1} $$ |