Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{\sqrt{8}}{4\sqrt{5}+3\sqrt{2}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{\sqrt{8}}{4\sqrt{5}+3\sqrt{2}}\frac{4\sqrt{5}-3\sqrt{2}}{4\sqrt{5}-3\sqrt{2}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{8\sqrt{10}-12}{80-12\sqrt{10}+12\sqrt{10}-18} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{8\sqrt{10}-12}{62}\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ 4 \sqrt{5}- 3 \sqrt{2}} $$. |
② | Multiply in a numerator. $$ \color{blue}{ \sqrt{8} } \cdot \left( 4 \sqrt{5}- 3 \sqrt{2}\right) = \color{blue}{ \sqrt{8}} \cdot 4 \sqrt{5}+\color{blue}{ \sqrt{8}} \cdot- 3 \sqrt{2} = \\ = 8 \sqrt{10}-12 $$ Simplify denominator. $$ \color{blue}{ \left( 4 \sqrt{5} + 3 \sqrt{2}\right) } \cdot \left( 4 \sqrt{5}- 3 \sqrt{2}\right) = \color{blue}{ 4 \sqrt{5}} \cdot 4 \sqrt{5}+\color{blue}{ 4 \sqrt{5}} \cdot- 3 \sqrt{2}+\color{blue}{ 3 \sqrt{2}} \cdot 4 \sqrt{5}+\color{blue}{ 3 \sqrt{2}} \cdot- 3 \sqrt{2} = \\ = 80- 12 \sqrt{10} + 12 \sqrt{10}-18 $$ |
③ | Simplify numerator and denominator |