| $$ \begin{aligned}-10-3i-7-5i& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-8i-17\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{-10} \color{red}{-3i} \color{blue}{-7} \color{red}{-5i} = \color{red}{-8i} \color{blue}{-17} $$ |