Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{9}{3\sqrt{13}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{9}{3\sqrt{13}}\frac{\sqrt{13}}{\sqrt{13}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{9\sqrt{13}}{39} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{ 9 \sqrt{ 13 } : \color{blue}{ 3 } } { 39 : \color{blue}{ 3 }} \xlongequal{ } \\[1 em] & \xlongequal{ }\frac{3\sqrt{13}}{13}\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ \sqrt{13}} $$. |
② | Multiply in a numerator. $$ \color{blue}{ 9 } \cdot \sqrt{13} = 9 \sqrt{13} $$ Simplify denominator. $$ \color{blue}{ 3 \sqrt{13} } \cdot \sqrt{13} = 39 $$ |
③ | Divide numerator and denominator by $ \color{blue}{ 3 } $. |