Evaluate
\frac{4\sqrt{21}}{21}\approx 0.872871561
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\frac{\sqrt{16}}{\sqrt{21}}
Rewrite the square root of the division \sqrt{\frac{16}{21}} as the division of square roots \frac{\sqrt{16}}{\sqrt{21}}.
\frac{4}{\sqrt{21}}
Calculate the square root of 16 and get 4.
\frac{4\sqrt{21}}{\left(\sqrt{21}\right)^{2}}
Rationalize the denominator of \frac{4}{\sqrt{21}} by multiplying numerator and denominator by \sqrt{21}.
\frac{4\sqrt{21}}{21}
The square of \sqrt{21} is 21.
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