Tap the blue circles to see an explanation.
| $$ \begin{aligned}(1+2\sqrt{2})^3& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}1+2\sqrt{2}+2\sqrt{2}+8+2\sqrt{2}+8+8+16\sqrt{2} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}25+22\sqrt{2}\end{aligned} $$ | |
| ① | Multiply $ (1+2\sqrt{2})^3 $ by itself 3 times |
| ② | Combine like terms |