Question

Answer 1

a: Ta có: \(4\sqrt{20}+2\sqrt{45}-8\sqrt{5}+2\sqrt{180}\)

\(=8\sqrt{5}+6\sqrt{5}-8\sqrt{5}+12\sqrt{5}\)

\(=18\sqrt{5}\)

b: Ta có: \(\left(\dfrac{\sqrt{14}-\sqrt{7}}{1-\sqrt{2}}+\dfrac{\sqrt{15}-\sqrt{5}}{1-\sqrt{3}}\right):\dfrac{1}{\sqrt{12-2\sqrt{35}}}\)

\(=-\left(\sqrt{7}+\sqrt{5}\right)\left(\sqrt{7}-\sqrt{5}\right)\)

=-2