431. Упростить: 1) \(\frac{\sqrt{27}}{\sqrt{3}}\); 2) \(\frac{\sqrt{128}}{\sqrt{8}}\); 3) \(\frac{4\sqrt{40}}{\sqrt{10}}\); 4) \(\frac{20\sqrt{18}}{5\sqrt{2}}\).

1. \(\frac{\sqrt{27}}{\sqrt{3}}=\sqrt{\frac{27}{3}}=\sqrt{9}=3\).
2. \(\frac{\sqrt{128}}{\sqrt{8}}=\sqrt{\frac{128}{8}}=\sqrt{16}=4\).
3. \(\frac{4\sqrt{40}}{\sqrt{10}}=4\sqrt{\frac{40}{10}}=4\cdot2=8\).
4. \(\frac{20\sqrt{18}}{5\sqrt{2}}=4\sqrt{\frac{18}{2}}=4\cdot3=12\).

Ответ: 1) 3; 2) 4; 3) 8; 4) 12.