第38页

信息发布者：
3
$2-4a$
$-3\sqrt{2}＜-2\sqrt{3}＜-0.13＜3.14＜π$
$\sqrt{-y}$
$-3＜a≤0$
$6\sqrt{2}+2\sqrt{3}$
3
1
16202
解：​$(1)$​
$\begin{aligned} (\sqrt{20} - 2\sqrt{\frac{1}{5}})×\sqrt{10} &= \sqrt{20}×\sqrt{10} - 2\sqrt{\frac{1}{5}}×\sqrt{10} \\ &= \sqrt{200} - 2\sqrt{2} \\ &= 10\sqrt{2} - 2\sqrt{2} \\ &= 8\sqrt{2} \end{aligned}$
解：​$(2)$​
$\begin{aligned} (\sqrt{5}+\sqrt{6}-\sqrt{3})(\sqrt{6}-\sqrt{5}+\sqrt{3})&=[\sqrt{6}+(\sqrt{5}-\sqrt{3})][\sqrt{6}-(\sqrt{5}-\sqrt{3})]\\ &=(\sqrt{6})^2 - (\sqrt{5}-\sqrt{3})^2\\ &=6-(5-2\sqrt{15}+3)\\ &=6-8+2\sqrt{15}\\ &=-2+2\sqrt{15} \end{aligned}$
解：​$(3)$​
$\begin{aligned} (\sqrt{3}-\sqrt{2})^2+\sqrt{24}-6\sqrt{\frac{1}{3}}&=3-2\sqrt{6}+2+2\sqrt{6}-2\sqrt{3}\\ &=5-2\sqrt{3} \end{aligned}$
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