| $$ \begin{aligned}3x^3y^2-627y^4x^2z^5& \xlongequal{ }3x^3y^2-162x^2y^4z^5 \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-162x^2y^4z^5+3x^3y^2\end{aligned} $$ | |
| ① | Combine like terms: $$ -162x^2y^4z^5+3x^3y^2 = -162x^2y^4z^5+3x^3y^2 $$ |