$$ \begin{aligned}-1-8i-4-i& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-9i-5\end{aligned} $$ | |
① | Combine like terms: $$ \color{blue}{-1} \color{red}{-8i} \color{blue}{-4} \color{red}{-i} = \color{red}{-9i} \color{blue}{-5} $$ |