Evaluate
7-2\sqrt{6}\approx 2.101020514
Expand
7-2\sqrt{6}
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\left(\sqrt{6}\right)^{2}-2\sqrt{6}+1
Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(\sqrt{6}-1\right)^{2}.
6-2\sqrt{6}+1
The square of \sqrt{6} is 6.
7-2\sqrt{6}
Add 6 and 1 to get 7.
\left(\sqrt{6}\right)^{2}-2\sqrt{6}+1
Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(\sqrt{6}-1\right)^{2}.
6-2\sqrt{6}+1
The square of \sqrt{6} is 6.
7-2\sqrt{6}
Add 6 and 1 to get 7.
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