$$ \begin{aligned}-\sqrt{2}\cdot(6+4\sqrt{11})& \xlongequal{ }-(6\sqrt{2}+4\sqrt{22}) \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}-6\sqrt{2}-4\sqrt{22}\end{aligned} $$ | |
① | Remove the parenthesis by changing the sign of each term within them. |