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