5 целых 2/7 - 1/3 + 6 целых

5 целых 2/7 - 1/3 + 6 = 37/7 - 1/3 + 6 = (37×3 - 1×7 + 6×21)/21 = (111 - 7 + 126)/21 = 230/21 = 10 целых 20/21