Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{9}{\sqrt{10}+3}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{9}{\sqrt{10}+3}\frac{\sqrt{10}-3}{\sqrt{10}-3} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{9\sqrt{10}-27}{10-3\sqrt{10}+3\sqrt{10}-9} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{9\sqrt{10}-27}{1} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}9\sqrt{10}-27\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ \sqrt{10}-3} $$. |
② | Multiply in a numerator. $$ \color{blue}{ 9 } \cdot \left( \sqrt{10}-3\right) = \color{blue}{9} \cdot \sqrt{10}+\color{blue}{9} \cdot-3 = \\ = 9 \sqrt{10}-27 $$ Simplify denominator. $$ \color{blue}{ \left( \sqrt{10} + 3\right) } \cdot \left( \sqrt{10}-3\right) = \color{blue}{ \sqrt{10}} \cdot \sqrt{10}+\color{blue}{ \sqrt{10}} \cdot-3+\color{blue}{3} \cdot \sqrt{10}+\color{blue}{3} \cdot-3 = \\ = 10- 3 \sqrt{10} + 3 \sqrt{10}-9 $$ |
③ | Simplify numerator and denominator |
④ | Remove 1 from denominator. |