18 Вычислите: rac{14}{45} : (rac{9}{20} + rac{2}{15})

1. НОК(20, 15) = 60. 2. rac{9}{20} + rac{2}{15} = rac{9 · 3}{60} + rac{2 · 4}{60} = rac{27+8}{60} = rac{35}{60} = rac{7}{12}. 3. rac{14}{45} : rac{7}{12} = rac{14}{45} · rac{12}{7} = rac{168}{315} = rac{8}{15}