a) Ta có: \(A=\dfrac{4\sqrt{6}-2\sqrt{10}}{2\sqrt{2}}+\dfrac{4}{\sqrt{3}-\sqrt{5}}+3\sqrt{6-2\sqrt{5}}\)
\(=\dfrac{2\sqrt{2}\left(2\sqrt{3}-\sqrt{5}\right)}{2\sqrt{2}}-\dfrac{4\left(\sqrt{5}+\sqrt{3}\right)}{2}+3\left(\sqrt{5}-1\right)\)
\(=2\sqrt{3}-2\sqrt{5}-2\sqrt{5}-2\sqrt{3}+3\sqrt{5}-3\)
\(=-\sqrt{5}-3\)
b) Ta có: \(B=3\tan67^0+5\cdot\cos^216^0-3\cdot\cot23^0+5\cdot\cos^274^0-\dfrac{\cot37^0}{\tan53^0}\)
\(=3\tan67^0-3\tan67^0+5\cdot\left(\sin^274^0+\cos^274^0\right)-1\)
\(=5-1=4\)
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