Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{\sqrt{5}+8}{\sqrt{3}+7}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{\sqrt{5}+8}{\sqrt{3}+7}\frac{\sqrt{3}-7}{\sqrt{3}-7} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{\sqrt{15}-7\sqrt{5}+8\sqrt{3}-56}{3-7\sqrt{3}+7\sqrt{3}-49} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{\sqrt{15}-7\sqrt{5}+8\sqrt{3}-56}{-46} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle4}{\textcircled {4}} } }}}\frac{-\sqrt{15}+7\sqrt{5}-8\sqrt{3}+56}{46}\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ \sqrt{3}-7} $$. |
② | Multiply in a numerator. $$ \color{blue}{ \left( \sqrt{5} + 8\right) } \cdot \left( \sqrt{3}-7\right) = \color{blue}{ \sqrt{5}} \cdot \sqrt{3}+\color{blue}{ \sqrt{5}} \cdot-7+\color{blue}{8} \cdot \sqrt{3}+\color{blue}{8} \cdot-7 = \\ = \sqrt{15}- 7 \sqrt{5} + 8 \sqrt{3}-56 $$ Simplify denominator. $$ \color{blue}{ \left( \sqrt{3} + 7\right) } \cdot \left( \sqrt{3}-7\right) = \color{blue}{ \sqrt{3}} \cdot \sqrt{3}+\color{blue}{ \sqrt{3}} \cdot-7+\color{blue}{7} \cdot \sqrt{3}+\color{blue}{7} \cdot-7 = \\ = 3- 7 \sqrt{3} + 7 \sqrt{3}-49 $$ |
③ | Simplify numerator and denominator |
④ | Multiply both numerator and denominator by -1. |