3/5 + 1/3 - 4/30

3/5 + 1/3 - 4/30 = (3*6)/(5*6) + (1*10)/(3*10) - 4/30 = 18/30 + 10/30 - 4/30 = 28/30 - 4/30 = 24/30 = 4/5

Ответ: 4/5