| $$ \begin{aligned}3\sqrt{252}^{\sqrt{5}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}3(6\sqrt{7})^{\sqrt{5}}\end{aligned} $$ | |
| ① | $$ \sqrt{252} =
\sqrt{ 6 ^2 \cdot 7 } =
\sqrt{ 6 ^2 } \, \sqrt{ 7 } =
6 \sqrt{ 7 }$$ |