Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{2\sqrt{3}}{5+\sqrt{2}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{2\sqrt{3}}{5+\sqrt{2}}\frac{5-\sqrt{2}}{5-\sqrt{2}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{10\sqrt{3}-2\sqrt{6}}{25-5\sqrt{2}+5\sqrt{2}-2} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{10\sqrt{3}-2\sqrt{6}}{23}\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ 5- \sqrt{2}} $$. |
② | Multiply in a numerator. $$ \color{blue}{ 2 \sqrt{3} } \cdot \left( 5- \sqrt{2}\right) = \color{blue}{ 2 \sqrt{3}} \cdot5+\color{blue}{ 2 \sqrt{3}} \cdot- \sqrt{2} = \\ = 10 \sqrt{3}- 2 \sqrt{6} $$ Simplify denominator. $$ \color{blue}{ \left( 5 + \sqrt{2}\right) } \cdot \left( 5- \sqrt{2}\right) = \color{blue}{5} \cdot5+\color{blue}{5} \cdot- \sqrt{2}+\color{blue}{ \sqrt{2}} \cdot5+\color{blue}{ \sqrt{2}} \cdot- \sqrt{2} = \\ = 25- 5 \sqrt{2} + 5 \sqrt{2}-2 $$ |
③ | Simplify numerator and denominator |