\(\sqrt{\left(1-\sqrt{2}\right)^2}-\sqrt{9-4\sqrt{2}}\)
\(=\left|1-\sqrt{2}\right|-\sqrt{\left(2\sqrt{2}\right)^2-2\cdot2\sqrt{2}\cdot1+1^2}\)
\(=\sqrt{2}-1-\sqrt{\left(2\sqrt{2}-1\right)^2}\)
\(=\sqrt{2}-1-\left|2\sqrt{2}-1\right|\)
\(=\sqrt{2}-1-2\sqrt{2}+1\)
\(=-\sqrt{2}\)
\(---\)
\(\dfrac{1}{3+\sqrt{5}}+\dfrac{1}{3-\sqrt{5}}\)
\(=\dfrac{3-\sqrt{5}}{9-5}+\dfrac{3+\sqrt{5}}{9-5}\)
\(=\dfrac{3-\sqrt{5}+3+\sqrt{5}}{4}\)
\(=\dfrac{6}{4}\)
\(=\dfrac{3}{2}\)
#\(Toru\)
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