Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{2+\sqrt{5}}{6-\sqrt{3}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{2+\sqrt{5}}{6-\sqrt{3}}\frac{6+\sqrt{3}}{6+\sqrt{3}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{12+2\sqrt{3}+6\sqrt{5}+\sqrt{15}}{36+6\sqrt{3}-6\sqrt{3}-3} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{12+2\sqrt{3}+6\sqrt{5}+\sqrt{15}}{33}\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ 6 + \sqrt{3}} $$. |
② | Multiply in a numerator. $$ \color{blue}{ \left( 2 + \sqrt{5}\right) } \cdot \left( 6 + \sqrt{3}\right) = \color{blue}{2} \cdot6+\color{blue}{2} \cdot \sqrt{3}+\color{blue}{ \sqrt{5}} \cdot6+\color{blue}{ \sqrt{5}} \cdot \sqrt{3} = \\ = 12 + 2 \sqrt{3} + 6 \sqrt{5} + \sqrt{15} $$ Simplify denominator. $$ \color{blue}{ \left( 6- \sqrt{3}\right) } \cdot \left( 6 + \sqrt{3}\right) = \color{blue}{6} \cdot6+\color{blue}{6} \cdot \sqrt{3}\color{blue}{- \sqrt{3}} \cdot6\color{blue}{- \sqrt{3}} \cdot \sqrt{3} = \\ = 36 + 6 \sqrt{3}- 6 \sqrt{3}-3 $$ |
③ | Simplify numerator and denominator |