Bài 2:
1: \(=6\sqrt{2}+\sqrt{4.5-4\sqrt{2}}-9\sqrt{2}\)
\(=-3\sqrt{2}+\sqrt{9-8\sqrt{2}}\)
2: \(=\dfrac{1}{2}\cdot4\sqrt{3}-2\cdot5\sqrt{3}-\sqrt{3}+5\cdot\sqrt{\dfrac{4}{3}}\)
\(=2\sqrt{3}-10\sqrt{3}-\sqrt{3}+5\cdot\dfrac{2\sqrt{3}}{3}\)
\(=-\dfrac{17}{3}\sqrt{3}\)