| $$ \begin{aligned}(6x)^2+(6y)^2& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}36x^2+36y^2\end{aligned} $$ | |
| ① | $$ \left( 6x \right)^2 = 6^2x^2 = 36x^2 $$$$ \left( 6y \right)^2 = 6^2y^2 = 36y^2 $$ |