(49 2/9-25)-(11 4/7-2/3)=

Переводим смешанные дроби в неправильные:

$(49\frac{2}{9} - 24\frac{9}{9}) - (\frac{81}{7} - \frac{2}{3}) = 13\frac{20}{63}$

1) $48\frac{11}{9} - 24\frac{9}{9} = 24\frac{2}{9}$

2) $\frac{81}{7} - \frac{2}{3} = \frac{243}{21} - \frac{14}{21} = \frac{229}{21} = 10\frac{19}{21}$

НОЗ: 21

3) $\frac{218}{9} - \frac{229}{21} = \frac{1526}{63} - \frac{687}{63} = \frac{839}{63} = 13\frac{20}{63}$

НОЗ: 63