Evaluate
4\sqrt{7}+11\approx 21.583005244
Expand
4 \sqrt{7} + 11 = 21.583005244
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4+4\sqrt{7}+\left(\sqrt{7}\right)^{2}
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(2+\sqrt{7}\right)^{2}.
4+4\sqrt{7}+7
The square of \sqrt{7} is 7.
11+4\sqrt{7}
Add 4 and 7 to get 11.
4+4\sqrt{7}+\left(\sqrt{7}\right)^{2}
Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(2+\sqrt{7}\right)^{2}.
4+4\sqrt{7}+7
The square of \sqrt{7} is 7.
11+4\sqrt{7}
Add 4 and 7 to get 11.
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