Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{7\sqrt{3}}{\sqrt{10}+\sqrt{3}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{7\sqrt{3}}{\sqrt{10}+\sqrt{3}}\frac{\sqrt{10}-\sqrt{3}}{\sqrt{10}-\sqrt{3}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{7\sqrt{30}-21}{10-\sqrt{30}+\sqrt{30}-3} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{7\sqrt{30}-21}{7} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}\frac{\sqrt{30}-3}{1} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle5}{\textcircled {5}} } }}}\sqrt{30}-3\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ \sqrt{10}- \sqrt{3}} $$. |
② | Multiply in a numerator. $$ \color{blue}{ 7 \sqrt{3} } \cdot \left( \sqrt{10}- \sqrt{3}\right) = \color{blue}{ 7 \sqrt{3}} \cdot \sqrt{10}+\color{blue}{ 7 \sqrt{3}} \cdot- \sqrt{3} = \\ = 7 \sqrt{30}-21 $$ Simplify denominator. $$ \color{blue}{ \left( \sqrt{10} + \sqrt{3}\right) } \cdot \left( \sqrt{10}- \sqrt{3}\right) = \color{blue}{ \sqrt{10}} \cdot \sqrt{10}+\color{blue}{ \sqrt{10}} \cdot- \sqrt{3}+\color{blue}{ \sqrt{3}} \cdot \sqrt{10}+\color{blue}{ \sqrt{3}} \cdot- \sqrt{3} = \\ = 10- \sqrt{30} + \sqrt{30}-3 $$ |
③ | Simplify numerator and denominator |
④ | Divide both numerator and denominator by 7. |
⑤ | Remove 1 from denominator. |