помогииитеее пожалуйста дробии тут

1. 7 - 3/5 + 2 7/9 = 6 5/5 - 3/5 + 2 7/9 = 6 2/5 + 2 7/9 = 9 8/45
2. 5 2/7 - 1/3 + 6 = 4  20/21 + 6 = 10 20/21
3. 9 + 1 3/4 - 2/5 = 10 3/4 - 2/5 = 10 7/20
4. 3 5/12 - 4/5 + 31/60 = 2 37/60 + 31/60 = 2 68/60 = 2 17/15 = 3 2/15