Вычислите дроби. 3/20+7/30+9/50
3/20 + 7/30 = (3 × 3 + 7 × 2)/60 = 9/60 + 14/60 = 23/60 23/60 + 9/50 =(23 × 5 + 9 × 6)/300 = 115/300 + 54/300 = 169/300 Ответ 169/300