[tex]\sqrt3\cdot\sqrt{5}\cdot\sqrt{15}=\sqrt{3\cdot5\cdot15}=\sqrt{15\cdot15}=15\\\\\sqrt{\frac{4}{5}}\cdot\sqrt{0,6}\cdot\sqrt{12}=\sqrt{\frac{4}{5}\cdot\frac{6}{10}\cdot12}=\sqrt{\frac{144}{25}}=\frac{12}{5}=2\frac{2}{5}[/tex]
