381. Упростите дроби: 1) \(\frac{4\sqrt{72}}{3\sqrt{8}}\); 2) \(\frac{2\sqrt{63}}{\sqrt{28}}\); 3) \(\frac{2\sqrt{45}}{\sqrt{80}}\); 4) \(\frac{4\sqrt{99}}{9\sqrt{44}}\).

1. \(\frac{4\sqrt{72}}{3\sqrt{8}}=\frac{4}{3}\sqrt{\frac{72}{8}}=\frac{4}{3}\sqrt{9}=4\).
2. \(\frac{2\sqrt{63}}{\sqrt{28}}=2\sqrt{\frac{63}{28}}=2\sqrt{\frac{9}{4}}=3\).
3. \(\frac{2\sqrt{45}}{\sqrt{80}}=2\sqrt{\frac{45}{80}}=2\sqrt{\frac{9}{16}}=\frac{3}{2}\).
4. \(\frac{4\sqrt{99}}{9\sqrt{44}}=\frac{4}{9}\sqrt{\frac{99}{44}}=\frac{4}{9}\sqrt{\frac{9}{4}}=\frac{2}{3}\).

Ответ: 1) 4; 2) 3; 3) \(\frac{3}{2}\); 4) \(\frac{2}{3}\).