Evaluate
\sqrt{21}\approx 4.582575695
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2\times 2\sqrt{3}\times \frac{\sqrt{7}}{4}
Factor 12=2^{2}\times 3. Rewrite the square root of the product \sqrt{2^{2}\times 3} as the product of square roots \sqrt{2^{2}}\sqrt{3}. Take the square root of 2^{2}.
4\sqrt{3}\times \frac{\sqrt{7}}{4}
Multiply 2 and 2 to get 4.
\sqrt{7}\sqrt{3}
Cancel out 4 and 4.
\sqrt{21}
To multiply \sqrt{7} and \sqrt{3}, multiply the numbers under the square root.
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