Ответ:

а) НОК(30, 24) = 120: \(\frac{11}{30}=\frac{44}{120}\), \(\frac{7}{24}=\frac{35}{120}\).

б) НОК(34, 51) = 102: \(\frac{9}{34}=\frac{27}{102}\), \(\frac{8}{51}=\frac{16}{102}\).

в) НОК(14, 21, 28) = 84: \(\frac{9}{14}=\frac{54}{84}\), \(\frac{10}{21}=\frac{40}{84}\), \(\frac{15}{28}=\frac{45}{84}\).

Ответ: а) \(\frac{44}{120},\frac{35}{120}\); б) \(\frac{27}{102},\frac{16}{102}\); в) \(\frac{54}{84},\frac{40}{84},\frac{45}{84}\).