Ответ:

  1. \(\frac{30}{40}=\frac{30:10}{40:10}=\frac{3}{4}\).
  2. \(\frac{70}{15}=\frac{70:5}{15:5}=\frac{14}{3}\).
  3. \(\frac{125}{135}=\frac{125:5}{135:5}=\frac{25}{27}\).
  4. \(\frac{124}{240}=\frac{124:4}{240:4}=\frac{31}{60}\).
  5. \(\frac{254}{628}=\frac{254:2}{628:2}=\frac{127}{314}\).

Ответ: а) \(\frac{3}{4}\); б) \(\frac{14}{3}\); в) \(\frac{25}{27}\); г) \(\frac{31}{60}\); д) \(\frac{127}{314}\).