Ответ:

  1. \(\frac{56}{91}=\frac{56:7}{91:7}=\frac{8}{13}\).
  2. \(\frac{65}{125}=\frac{65:5}{125:5}=\frac{13}{25}\).
  3. \(\frac{121}{165}=\frac{121:11}{165:11}=\frac{11}{15}\).

Ответ: а) \(\frac{8}{13}\); б) \(\frac{13}{25}\); в) \(\frac{11}{15}\).