Ответ:

  1. \(\sqrt[3]{\frac{27}{64}}=\frac{\sqrt[3]{27}}{\sqrt[3]{64}}=\frac{3}{4}\).
  2. \(\sqrt[4]{\frac{625}{81}}=\frac{\sqrt[4]{625}}{\sqrt[4]{81}}=\frac{5}{3}\).
  3. \(\sqrt[3]{-\frac{27}{8}}=-\frac{\sqrt[3]{27}}{\sqrt[3]{8}}=-\frac{3}{2}\).
  4. \(\sqrt[4]{\frac{256}{81}}=\frac{\sqrt[4]{256}}{\sqrt[4]{81}}=\frac{4}{3}\).

Ответ: 1) \(\frac{3}{4}\); 2) \(\frac{5}{3}\); 3) \(-\frac{3}{2}\); 4) \(\frac{4}{3}\).