Ответ:

а) \(2\sqrt{81}-\frac{\sqrt{225}}{18}+\sqrt{0.16}=2\cdot9-\frac{15}{18}+0.4=18-\frac{5}{6}+\frac{2}{5}=\frac{527}{30}\).

б) \(\sqrt{8}\cdot\frac{\sqrt{225}}{\sqrt{18}}=\sqrt{8}\cdot\frac{15}{3\sqrt{2}}=\frac{15\sqrt{8}}{3\sqrt{2}}=5\cdot2=10\).

в) \(\frac{\sqrt{108}}{\sqrt{3}}=\sqrt{\frac{108}{3}}=\sqrt{36}=6\).

Ответ: а) \(\frac{527}{30}\); б) \(10\); в) \(6\).