5 6/13 - 1 11/13 = у+ 4 8/11 = 10 7/11
1) 5. 6/13 - 1. 11/13 = 3. 8/13 2) у + 4. 8/11 = 10. 7/11 у = 10. 7/11 - 4. 8/11 у = 5. 10/11