Bài 1:
a) \(2\sqrt{18}-7\sqrt{32}-\sqrt{72}+3\sqrt{8}\)
\(=2\sqrt{9.2}-7\sqrt{16.2}-\sqrt{36.2}+3\sqrt{4.2}\)
\(=6\sqrt{2}-28\sqrt{2}-6\sqrt{2}+6\sqrt{2}\)
\(=-22\sqrt{2}\)
b) \(\sqrt{\left(1+2\sqrt{3}\right)^2-\sqrt{4+2\sqrt{3}}}\)
\(=1+2\sqrt{3}-\sqrt{\left(\sqrt{3}+1\right)^2}\)
\(=1+2\sqrt{3}-\sqrt{3}-1\)
\(=\sqrt{3}\)
c) \(\dfrac{5\sqrt{3}-3}{5-\sqrt{3}}-\dfrac{4}{\sqrt{3}+\sqrt{7}}-\dfrac{6}{\sqrt{3}}\)
\(=\dfrac{\sqrt{3}\left(5-\sqrt{3}\right)}{5-\sqrt{3}}-\dfrac{4\left(\sqrt{7}-\sqrt{3}\right)}{7-3}-2\sqrt{3}\)
\(=5-\sqrt{3}-\sqrt{7}+\sqrt{3}-2\sqrt{3}\)
\(=5-\sqrt{7}-2\sqrt{3}\)