Ответ:

  1. \(\sqrt{\frac{57}{64}}=\frac{\sqrt{57}}{8}\).
  2. \(\sqrt{5\frac{1}{16}}=\sqrt{\frac{81}{16}}=\frac{9}{4}\).
  3. \(\sqrt{6\frac{19}{25}}=\sqrt{\frac{169}{25}}=\frac{13}{5}\).
  4. \(\sqrt{72\frac{1}{4}}=\sqrt{\frac{289}{4}}=\frac{17}{2}\).

Ответ: а) \(\frac{\sqrt{57}}{8}\); б) \(\frac{9}{4}\); в) \(\frac{13}{5}\); г) \(\frac{17}{2}\).