8 целых 2/5 плюс 1 целая 1/5 сравним с 9 минус 3/5

8 2/5 * 1 1/5 = (8 * 5 + 2) / 5 * (1 * 5 + 1) / 5 = (40 + 2) / 5 * (5 + 1) / 5 = 42/5 * 6/5 = (42 * 6) / (5 * 5) = 252/25 = 10 (252 - 25 * 10) / 25 = 10 (252 - 250) / 25 = 10 2/25.

9 - 3/5 = 8 + 1 - 3/5 = 8 + 5/5 - 3/5 = 8 + (5 - 3) / 5 = 8 + 2/5 = 8 2/5.

Сравним получившийся результат:

10 2/25 > 8 2/5.

Решим подобное задание:

7 1/4 * 1 2/3 = (7 * 4 + 1) / 4 * (1 * 3 + 1) / 3 = (28 + 1) / 4 * (3 + 1) / 3 = 29/4 * 4/3 = 29/3 = 9 2/3.

11 - 3/4 = 10 + 1 - 3/4 = 10 + 4/4 - 3/4 = 10 + (4 - 3) / 4 = 10 + 1/4 = 10 1/4.

9 2/3 < 10 1/4.