Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{-5}{4+\sqrt{6}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{-5}{4+\sqrt{6}}\frac{4-\sqrt{6}}{4-\sqrt{6}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{-20+5\sqrt{6}}{16-4\sqrt{6}+4\sqrt{6}-6} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{-20+5\sqrt{6}}{10} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}\frac{-4+\sqrt{6}}{2}\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ 4- \sqrt{6}} $$. |
② | Multiply in a numerator. $$ \color{blue}{ -5 } \cdot \left( 4- \sqrt{6}\right) = \color{blue}{-5} \cdot4\color{blue}{-5} \cdot- \sqrt{6} = \\ = -20 + 5 \sqrt{6} $$ Simplify denominator. $$ \color{blue}{ \left( 4 + \sqrt{6}\right) } \cdot \left( 4- \sqrt{6}\right) = \color{blue}{4} \cdot4+\color{blue}{4} \cdot- \sqrt{6}+\color{blue}{ \sqrt{6}} \cdot4+\color{blue}{ \sqrt{6}} \cdot- \sqrt{6} = \\ = 16- 4 \sqrt{6} + 4 \sqrt{6}-6 $$ |
③ | Simplify numerator and denominator |
④ | Divide both numerator and denominator by 5. |