Question
Answer
$$\dfrac{8\sqrt{49}}{\sqrt{21}}=\dfrac{8\sqrt{21}}{3}$$
Explanation
Tap the blue circles to see an explanation.
| $$ \begin{aligned}\frac{8\sqrt{49}}{\sqrt{21}}& \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle1}{\textcircled {1}} } }}}\frac{8\sqrt{49}}{\sqrt{21}}\frac{\sqrt{21}}{\sqrt{21}} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle2}{\textcircled {2}} } }}}\frac{56\sqrt{21}}{21} \xlongequal{ } \\[1 em] & \xlongequal{ \color{blue}{ \text{\normalsize{ \htmlClass{explanationCircle explanationCircle3}{\textcircled {3}} } }}}\frac{ 56 \sqrt{ 21 } : \color{blue}{ 7 } } { 21 : \color{blue}{ 7 }} \xlongequal{ } \\[1 em] & \xlongequal{ }\frac{8\sqrt{21}}{3}\end{aligned} $$ | |
| ① | Multiply the numerator and denominator by the conjugate of the denominator . $$\color{blue}{ \sqrt{21}} $$. |
| ② | Multiply in a numerator. $$ \color{blue}{ 8 \sqrt{49} } \cdot \sqrt{21} = 56 \sqrt{21} $$ Simplify denominator. $$ \color{blue}{ \sqrt{21} } \cdot \sqrt{21} = 21 $$ |
| ③ | Divide numerator and denominator by $ \color{blue}{ 7 } $. |
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