Question
Answer
$$\dfrac{2}{8+\sqrt{10}}=\dfrac{8-\sqrt{10}}{27}$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}\frac{2}{8+\sqrt{10}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{2}{8+\sqrt{10}}\frac{8-\sqrt{10}}{8-\sqrt{10}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{16-2\sqrt{10}}{64-8\sqrt{10}+8\sqrt{10}-10} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{16-2\sqrt{10}}{54} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}\frac{8-\sqrt{10}}{27}\end{aligned} $$ | |
| ① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ 8- \sqrt{10}} $$. |
| ② | Multiply in a numerator. $$ \color{blue}{ 2 } \cdot \left( 8- \sqrt{10}\right) = \color{blue}{2} \cdot8+\color{blue}{2} \cdot- \sqrt{10} = \\ = 16- 2 \sqrt{10} $$ Simplify denominator. $$ \color{blue}{ \left( 8 + \sqrt{10}\right) } \cdot \left( 8- \sqrt{10}\right) = \color{blue}{8} \cdot8+\color{blue}{8} \cdot- \sqrt{10}+\color{blue}{ \sqrt{10}} \cdot8+\color{blue}{ \sqrt{10}} \cdot- \sqrt{10} = \\ = 64- 8 \sqrt{10} + 8 \sqrt{10}-10 $$ |
| ③ | Simplify numerator and denominator |
| ④ | Divide both numerator and denominator by 2. |
This page was created using
Rationalize Denominator Calculator