| $$ \begin{aligned}5x+2x+6y-4y& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}7x+2y\end{aligned} $$ | |
| ① | Combine like terms: $$ \color{blue}{5x} + \color{blue}{2x} + \color{red}{6y} \color{red}{-4y} = \color{blue}{7x} + \color{red}{2y} $$ |