91. Найдите значение выражения: 1) \(\sqrt{72}\cdot\sqrt{2}\); 2) \(\sqrt{360}\cdot\sqrt{490}\); 3) \(\frac{\sqrt{242}}{\sqrt{2}}\); 4) \(\frac{\sqrt{40}}{\sqrt{0,025}}\).

1. \(\sqrt{72}\cdot\sqrt2=\sqrt{144}=12\).
2. \(\sqrt{360}\cdot\sqrt{490}=\sqrt{360\cdot490}=6\sqrt{10}\cdot7\sqrt{10}=420\).
3. \(\frac{\sqrt{242}}{\sqrt2}=\sqrt{\frac{242}{2}}=\sqrt{121}=11\).
4. \(\frac{\sqrt{40}}{\sqrt{0.025}}=\sqrt{\frac{40}{0.025}}=\sqrt{1600}=40\).

Ответ: 1) 12; 2) 420; 3) 11; 4) 40.