\(\sqrt{27-8\sqrt{11}}\)-\(\sqrt{11}\)

b,

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NV
9 tháng 8 2021

\(\sqrt{27-8\sqrt{11}}-\sqrt{11}=\sqrt{\left(4-\sqrt{11}\right)^2}-\sqrt{11}=\left|4-\sqrt{11}\right|-\sqrt{11}=4-2\sqrt{11}\)

\(\sqrt{48-16\sqrt{8}}-\sqrt{8}=\sqrt{\left(4\sqrt{2}-4\right)^2}-2\sqrt{2}=\left|4\sqrt{2}-4\right|-2\sqrt{2}=2\sqrt{2}-4\)

9 tháng 8 2021

  \(\sqrt{27-8\sqrt{11}}-\sqrt{11}\\ =\sqrt{4^2-2.4.\sqrt{11}+\left(\sqrt{11}\right)^2}-\sqrt{11}\\ =\sqrt{\left(4-\sqrt{11}\right)^2}-\sqrt{11}\\ =\left|4-\sqrt{11}\right|-\sqrt{11}\\ =4-\sqrt{11}-\sqrt{11}=4-\left(-2\right)=6\)

 \(\sqrt{48-16\sqrt{8}}-\sqrt{8}\\ =\sqrt{\left(4\sqrt{2}\right)^2-2.4\sqrt{2}.4+4^2}-\sqrt{8}\\ =\sqrt{\left(4\sqrt{2}-4\right)^2}-\sqrt{8}\\ =\left|4\sqrt{2}-4\right|-\sqrt{8}\\ =4\sqrt{2}-4-\sqrt{8}=4\sqrt{2}-4-3\sqrt{2}\\ =\sqrt{2}-4\)

11 tháng 8 2020

a) \(\sqrt{11-6\sqrt{2}}-\sqrt{27+10\sqrt{2}}\)

\(=\sqrt{9-6\sqrt{2}+2}-\sqrt{25+10\sqrt{2}+2}\)

\(=\sqrt{\left(3-\sqrt{2}\right)^2}-\sqrt{\left(5+\sqrt{2}\right)^2}\)

\(=\left|3-\sqrt{2}\right|-\left|5+\sqrt{2}\right|\)

\(=3-\sqrt{2}-5-\sqrt{2}=-2-2\sqrt{2}\)

b) \(\sqrt{13-4\sqrt{3}}-\sqrt{16-8\sqrt{3}}\)

\(=\sqrt{12-4\sqrt{3}+1}-\sqrt{12-8\sqrt{3}+4}\)

\(=\sqrt{\left(2\sqrt{3}-1\right)^2}-\sqrt{\left(2\sqrt{3}-2\right)^2}\)

\(=\left|2\sqrt{3}-1\right|-\left|2\sqrt{3}-2\right|\)

\(=2\sqrt{3}-1-2\sqrt{3}+2\)

\(=1\)

13 tháng 6 2018

1.\(=5\sqrt{2}-3\sqrt{2}+10\sqrt{2}-9\sqrt{2}=3\sqrt{2}\)

2.\(=5\sqrt{5}+4\sqrt{5}-9\sqrt{5}=0\)

4 tháng 7 2018

\(1.A=\dfrac{1}{2}\sqrt{48}-2\sqrt{75}-\dfrac{\sqrt{33}}{\sqrt{11}}+5\sqrt{1\dfrac{1}{3}}=\dfrac{1}{2}\sqrt{\dfrac{1}{3}.144}-2\sqrt{\dfrac{1}{3}.225}-\sqrt{\dfrac{1}{3}.9}+5\sqrt{\dfrac{4}{3}}=6\sqrt{\dfrac{1}{3}}-30\sqrt{\dfrac{1}{3}}-3\sqrt{\dfrac{1}{3}}+10\sqrt{\dfrac{1}{3}}=-17\sqrt{\dfrac{1}{3}}\) \(2.B=\left(2\sqrt{27}-3\sqrt{48}+3\sqrt{75}-\sqrt{192}\right)\left(1-\sqrt{3}\right)=\left(6\sqrt{3}-12\sqrt{3}+15\sqrt{3}-8\sqrt{3}\right)\left(1-\sqrt{3}\right)=\sqrt{3}\left(1-\sqrt{3}\right)=\sqrt{3}-3\) \(3.C=\left(2\sqrt{7}-2\sqrt{6}\right).\sqrt{6}-\sqrt{168}=2\sqrt{42}-12-2\sqrt{42}=-12\) \(4.D=\left(\sqrt{28}-2\sqrt{8}+\sqrt{7}\right).\sqrt{7}+4\sqrt{14}=\left(3\sqrt{7}-4\sqrt{2}\right)\sqrt{7}=21-4\sqrt{14}+4\sqrt{14}=21\)