Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{3+\sqrt{3}}{4-\sqrt{5}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{3+\sqrt{3}}{4-\sqrt{5}}\frac{4+\sqrt{5}}{4+\sqrt{5}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{12+3\sqrt{5}+4\sqrt{3}+\sqrt{15}}{16+4\sqrt{5}-4\sqrt{5}-5} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{12+3\sqrt{5}+4\sqrt{3}+\sqrt{15}}{11}\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ 4 + \sqrt{5}} $$. |
② | Multiply in a numerator. $$ \color{blue}{ \left( 3 + \sqrt{3}\right) } \cdot \left( 4 + \sqrt{5}\right) = \color{blue}{3} \cdot4+\color{blue}{3} \cdot \sqrt{5}+\color{blue}{ \sqrt{3}} \cdot4+\color{blue}{ \sqrt{3}} \cdot \sqrt{5} = \\ = 12 + 3 \sqrt{5} + 4 \sqrt{3} + \sqrt{15} $$ Simplify denominator. $$ \color{blue}{ \left( 4- \sqrt{5}\right) } \cdot \left( 4 + \sqrt{5}\right) = \color{blue}{4} \cdot4+\color{blue}{4} \cdot \sqrt{5}\color{blue}{- \sqrt{5}} \cdot4\color{blue}{- \sqrt{5}} \cdot \sqrt{5} = \\ = 16 + 4 \sqrt{5}- 4 \sqrt{5}-5 $$ |
③ | Simplify numerator and denominator |