a) [tex]\sqrt{225 * 16} = \sqrt{25 * 9 *16} = \sqrt{5^{2}*3^{2} * 4^2} =5*3*4 = 60[/tex]
b) [tex]\sqrt[3]{-\frac{8}{27} } = - \frac{2}{3}[/tex]
c) [tex]7\sqrt{5} - 12\sqrt{5} - \sqrt{5} = -6\sqrt{5}[/tex]
