$$ \begin{aligned}x+x^2+x^3+x^4+x^5+x^{60}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}x^{60}+x^5+x^4+x^3+x^2+x\end{aligned} $$ | |
① | Combine like terms: $$ x^{60}+x^5+x^4+x^3+x^2+x = x^{60}+x^5+x^4+x^3+x^2+x $$ |