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一道初中题——根式化简

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hbghlyj Posted 2020-4-8 22:16 |Read mode
$7\sqrt{2(161-24\sqrt{2})}+\sqrt[4]2\sqrt{48+161\sqrt{2}}+14\sqrt{161-\sqrt{24769}}=8\sqrt{2(161+24\sqrt{2})}$

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tommywong Posted 2020-4-10 12:10
對$\sqrt{161-\sqrt{24769}}$開方就證到架喇

個核心價值就係$\displaystyle\sqrt{a-\sqrt{b}}=\frac{\sqrt{a+\sqrt{a^2-b}}-\sqrt{a-\sqrt{a^2-b}}}{\sqrt{2}}$

$\displaystyle\sqrt{161-\sqrt{24769}}=\frac{\sqrt{161+24\sqrt{2}}-\sqrt{161-24\sqrt{2}}}{\sqrt{2}}$

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力工 Posted 2020-4-10 12:23
回复 2# tommywong
大佬!好墙!

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