$$ \begin{aligned}\sqrt{2}\cdot(5+\sqrt{2})& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}5\sqrt{2}+2\end{aligned} $$ | |
① | $$ \color{blue}{ \sqrt{2} } \cdot \left( 5 + \sqrt{2}\right) = \color{blue}{ \sqrt{2}} \cdot5+\color{blue}{ \sqrt{2}} \cdot \sqrt{2} = \\ = 5 \sqrt{2} + 2 $$ |