[tex]\frac{4\sqrt{15}}{2\sqrt{5}} = 2\sqrt{\frac{15}{5}} = 2\sqrt{3}\\\\\\3\sqrt[3]{6}\cdot\sqrt[3]{2} = 3\sqrt[3]{6\cdot2} = 3\sqrt[3]{12}\\\\\\\frac{15\sqrt[3]{-6}}{3\sqrt[3]{3}} = \frac{-15\sqrt[3]{6}}{3\sqrt[3]{3}} = -5\sqrt[3]{\frac{6}{3}} = -5\sqrt[3]{2}[/tex]
