| $$ \begin{aligned}\frac{1}{\sqrt{6}-\sqrt{3}+2+1}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{1}{\sqrt{6}-\sqrt{3}+3}\end{aligned} $$ | |
| ① | Simplify numerator and denominator |