| $$ \begin{aligned}8cy-5c+6-3yc+c+y& \xlongequal{ }8cy-5c+6-3cy+c+y \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}5cy-4c+y+6\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{8cy} \color{red}{-5c} +6 \color{blue}{-3cy} + \color{red}{c} +y = \color{blue}{5cy} \color{red}{-4c} +y+6 $$ |