Tap the blue circles to see an explanation.
$$ \begin{aligned}\frac{\sqrt{7}}{\sqrt{40}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{\sqrt{7}}{\sqrt{40}}\frac{\sqrt{40}}{\sqrt{40}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{2\sqrt{70}}{40} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{\sqrt{70}}{20}\end{aligned} $$ | |
① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ \sqrt{40}} $$. |
② | Multiply in a numerator. $$ \color{blue}{ \sqrt{7} } \cdot \sqrt{40} = 2 \sqrt{70} $$ Simplify denominator. $$ \color{blue}{ \sqrt{40} } \cdot \sqrt{40} = 40 $$ |
③ | Divide both numerator and denominator by 2. |