Evaluate
\left(-x+2\sqrt{5}\right)^{2}
Expand
x^{2}-4\sqrt{5}x+20
Graph
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4\left(\sqrt{5}\right)^{2}-4\sqrt{5}x+x^{2}
Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(2\sqrt{5}-x\right)^{2}.
4\times 5-4\sqrt{5}x+x^{2}
The square of \sqrt{5} is 5.
20-4\sqrt{5}x+x^{2}
Multiply 4 and 5 to get 20.
4\left(\sqrt{5}\right)^{2}-4\sqrt{5}x+x^{2}
Use binomial theorem \left(a-b\right)^{2}=a^{2}-2ab+b^{2} to expand \left(2\sqrt{5}-x\right)^{2}.
4\times 5-4\sqrt{5}x+x^{2}
The square of \sqrt{5} is 5.
20-4\sqrt{5}x+x^{2}
Multiply 4 and 5 to get 20.
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