| $$ \begin{aligned}3x-1+2xy^2+xy-2y& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}2xy^2+xy+3x-2y-1\end{aligned} $$ | |
| ① | Combine like terms: $$ 3x-1+2xy^2+xy-2y = 2xy^2+xy+3x-2y-1 $$ |