Question

10．计算：3$\sqrt{48}$-9$\sqrt{\frac{1}{3}}$+3$\sqrt{18}$-4$\sqrt{\frac{1}{8}}$．

Answer 1

分析 首先化简二次根式进而合并同类二次根式求出答案．

解答 解：3$\sqrt{48}$-9$\sqrt{\frac{1}{3}}$+3$\sqrt{18}$-4$\sqrt{\frac{1}{8}}$
=3×4$\sqrt{3}$-9×$\frac{\sqrt{3}}{3}$+3×3$\sqrt{2}$-4×$\frac{\sqrt{2}}{4}$
=12$\sqrt{3}$-3$\sqrt{3}$+9$\sqrt{2}$-$\sqrt{2}$
=9$\sqrt{3}$+8$\sqrt{2}$．

点评 此题主要考查了二次根式的加减运算，正确化简二次根式是解题关键．