2. Найдите значение выражения: 1) \(0.3\sqrt{900}-\frac{1}{4}\sqrt{64}\); 2) \(\sqrt{0.64\cdot49}\); 3) \(\sqrt{3^4\cdot2^6}\); 4) \(\sqrt{40}\cdot\sqrt{10}-\frac{\sqrt{20}}{\sqrt{5}}\).

1. \(0.3\sqrt{900}-\frac{1}{4}\sqrt{64}=0.3\cdot30-\frac{1}{4}\cdot8=9-2=7\).
2. \(\sqrt{0.64\cdot49}=\sqrt{0.64}\cdot\sqrt{49}=0.8\cdot7=5.6\).
3. \(\sqrt{3^4\cdot2^6}=\sqrt{3^4}\cdot\sqrt{2^6}=3^2\cdot2^3=9\cdot8=72\).
4. \(\sqrt{40}\cdot\sqrt{10}-\frac{\sqrt{20}}{\sqrt{5}}=\sqrt{400}-\sqrt{4}=20-2=18\).

Ответ: 1) 7; 2) 5.6; 3) 72; 4) 18.