Tap the blue circles to see an explanation.
| $$ \begin{aligned}\frac{9}{\sqrt{77}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}} \frac{ 9 }{\sqrt{ 77 }} \times \frac{ \color{orangered}{\sqrt{ 77 }} }{ \color{orangered}{\sqrt{ 77 }}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{9\sqrt{77}}{77}\end{aligned} $$ | |
| ① | Multiply both top and bottom by $ \color{orangered}{ \sqrt{ 77 }}$. |
| ② | In denominator we have $ \sqrt{ 77 } \cdot \sqrt{ 77 } = 77 $. |