Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{5-\sqrt{3}}{2+\sqrt{5}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{5-\sqrt{3}}{2+\sqrt{5}}\frac{2-\sqrt{5}}{2-\sqrt{5}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{10-5\sqrt{5}-2\sqrt{3}+\sqrt{15}}{4-2\sqrt{5}+2\sqrt{5}-5} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{10-5\sqrt{5}-2\sqrt{3}+\sqrt{15}}{-1} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}\frac{-10+5\sqrt{5}+2\sqrt{3}-\sqrt{15}}{1} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle5}{\textcircled {5}} } }}}-10+5\sqrt{5}+2\sqrt{3}-\sqrt{15}\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ 2- \sqrt{5}} $$. |
② | Multiply in a numerator. $$ \color{blue}{ \left( 5- \sqrt{3}\right) } \cdot \left( 2- \sqrt{5}\right) = \color{blue}{5} \cdot2+\color{blue}{5} \cdot- \sqrt{5}\color{blue}{- \sqrt{3}} \cdot2\color{blue}{- \sqrt{3}} \cdot- \sqrt{5} = \\ = 10- 5 \sqrt{5}- 2 \sqrt{3} + \sqrt{15} $$ Simplify denominator. $$ \color{blue}{ \left( 2 + \sqrt{5}\right) } \cdot \left( 2- \sqrt{5}\right) = \color{blue}{2} \cdot2+\color{blue}{2} \cdot- \sqrt{5}+\color{blue}{ \sqrt{5}} \cdot2+\color{blue}{ \sqrt{5}} \cdot- \sqrt{5} = \\ = 4- 2 \sqrt{5} + 2 \sqrt{5}-5 $$ |
③ | Simplify numerator and denominator |
④ | Multiply both numerator and denominator by -1. |
⑤ | Remove 1 from denominator. |