Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{1}{4\sqrt{3}-3\sqrt{5}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{1}{4\sqrt{3}-3\sqrt{5}}\frac{4\sqrt{3}+3\sqrt{5}}{4\sqrt{3}+3\sqrt{5}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{4\sqrt{3}+3\sqrt{5}}{48+12\sqrt{15}-12\sqrt{15}-45} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{4\sqrt{3}+3\sqrt{5}}{3}\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ 4 \sqrt{3} + 3 \sqrt{5}} $$. |
② | Multiply in a numerator. $$ \color{blue}{ 1 } \cdot \left( 4 \sqrt{3} + 3 \sqrt{5}\right) = \color{blue}{1} \cdot 4 \sqrt{3}+\color{blue}{1} \cdot 3 \sqrt{5} = \\ = 4 \sqrt{3} + 3 \sqrt{5} $$ Simplify denominator. $$ \color{blue}{ \left( 4 \sqrt{3}- 3 \sqrt{5}\right) } \cdot \left( 4 \sqrt{3} + 3 \sqrt{5}\right) = \color{blue}{ 4 \sqrt{3}} \cdot 4 \sqrt{3}+\color{blue}{ 4 \sqrt{3}} \cdot 3 \sqrt{5}\color{blue}{- 3 \sqrt{5}} \cdot 4 \sqrt{3}\color{blue}{- 3 \sqrt{5}} \cdot 3 \sqrt{5} = \\ = 48 + 12 \sqrt{15}- 12 \sqrt{15}-45 $$ |
③ | Simplify numerator and denominator |