(30 : 27 - 1/3) * 2 целых 1/7 + 2/5 = 2 целых 82/105
1) 30 : 27 = 30/27 = 1 целая 3/27 = 1 целая 1/9
2) 1 целая 1/9 * 2 целых 1/7 = 10/9 * 15/7 = (10*5)/(3*7) = 50/21 = 2 целых 8/21
3) 2 целых 8/21 + 2/5 = 2 целых 40/105 + 42/105 = 2 целых 82/105
