4. Выполните действия: а) \(\frac{38}{67} + \frac{28}{67}\); б) \(\frac{66}{71} - \(\frac{52}{71}\); в) \(\frac{19}{69} + \frac{11}{69}\); г) \(\frac{54}{85} + \frac{63}{85} - \frac{38}{85}\); д) \(\frac{22}{47} - \frac{17}{47} + \frac{11}{47}\).

1. а) \(\frac{38}{67} + \frac{28}{67} = \frac{38 + 28}{67} = \frac{66}{67}\).
2. б) \(\frac{66}{71} - \frac{52}{71} = \frac{66 - 52}{71} = \frac{14}{71}\).
3. в) \(\frac{19}{69} + \frac{11}{69} = \frac{19 + 11}{69} = \frac{30}{69} = \frac{10}{23}\).
4. г) \(\frac{54}{85} + \frac{63}{85} - \frac{38}{85} = \frac{54 + 63 - 38}{85} = \frac{79}{85}\).
5. д) \(\frac{22}{47} - \frac{17}{47} + \frac{11}{47} = \frac{22 - 17 + 11}{47} = \frac{16}{47}\).

Ответ: а) \(\frac{66}{67}\); б) \(\frac{14}{71}\); в) \(\frac{10}{23}\); г) \(\frac{79}{85}\); д) \(\frac{16}{47}\)