Evaluate
12\sqrt{7}\approx 31.749015733
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8\sqrt{7}+2\times 2\sqrt{7}
Factor 28=2^{2}\times 7. Rewrite the square root of the product \sqrt{2^{2}\times 7} as the product of square roots \sqrt{2^{2}}\sqrt{7}. Take the square root of 2^{2}.
8\sqrt{7}+4\sqrt{7}
Multiply 2 and 2 to get 4.
12\sqrt{7}
Combine 8\sqrt{7} and 4\sqrt{7} to get 12\sqrt{7}.
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