Пользователь9 лет назад
9/56 - (7/15 - 5/12) * (3/14 + 1/2) = 1/8;
По действиям:
1) 7/15 - 5/12 = 7/15 * 4/4 - 5/12 * 5/5 = 28/60 - 25/60 = 3/60 = 1/20;
2) 3/14 + 1/2 = 3/14 + 1/2 * 7/7 = 3/14 + 7/14 = 10/14 = 5/7;
3) 1/20 * 5/7 = 5/140 = 1/28;
4) 9/56 - 1/28 = 9/56 - 1/28 * 2/2 = 9/56 - 2/56 = 7/56 = 1/8.