17 дробь9(63дробь4-3,125:31дробь87,5-2 8дробь15

1 7/9 + (6 3/4 / 3,125 - 2,5 / 3 1/8) * 7,5 - 2 8/15 = 9 4/9.
Преобразуем:
2,5 = 2 5/10 = 25/10 на 5 = 5/2.
3 1/8 = (24 + 1)/8 = 25/8.
6 3/4 = (6 * 4 + 3)/4 = 27/4.
3,125 = 3 125/1000 = 3125/1000 на 125 = 25/8.
7,5 = 7 5/10 = 75/10 на 5 = 15/2.
1 7/9 = 16/9.
2 8/15 = 38/15.
Вычислим:
1. 5/2 / 25/8 = (5 * 8)/(2 * 25) = 40/50 на 10 = 4/5.
2. 27/4 / 25/8 = (27 * 8)/(4 * 25) = 216/100 на 4 = 54/25.
3. 54/25 - 4/5 = (54 - 20)/25 = 34/25.
4. 34/25 * 15/2 = (34 * 15)/(25 * 2) = 510/50 на 10 = 51/5.
5. 16/9 + 51/5 = (80 + 459)/45 = 539/45.
6. 539/45 - 38/15 = (539 - 114)/45 = 425/45 на 5 = 85/9 = 9 4/9.