Ответ:

  1. \(\frac{6}{25}\cdot\frac{15}{17}=\frac{18}{85}\).
  2. \(\frac{9}{26}\cdot\frac{13}{18}=\frac{1}{4}\).
  3. \(\frac{5}{11}\cdot\frac{22}{15}=\frac{2}{3}\).
  4. \(\frac{7}{12}\cdot\frac{8}{9}=\frac{56}{108}=\frac{14}{27}\).

Ответ: 18/85; 1/4; 2/3; 14/27.