Ответ:
а) НОК(9, 5) = 45: \(\frac{2}{9}=\frac{10}{45}\), \(\frac{3}{5}=\frac{27}{45}\).
б) НОК(7, 14) = 14: \(\frac{6}{7}=\frac{12}{14}\), \(\frac{9}{14}=\frac{9}{14}\).
в) НОК(28, 21) = 84: \(\frac{13}{28}=\frac{39}{84}\), \(\frac{8}{21}=\frac{32}{84}\).
г) НОК(504, 756) = 1512: \(\frac{1}{504}=\frac{3}{1512}\), \(\frac{1}{756}=\frac{2}{1512}\).
Ответ: а) \(\frac{10}{45},\frac{27}{45}\); б) \(\frac{12}{14},\frac{9}{14}\); в) \(\frac{39}{84},\frac{32}{84}\); г) \(\frac{3}{1512},\frac{2}{1512}\).
