Пошаговое объяснение:

17 3/15 - 8 7/20 +(9 11/15 -(2 1/15 - 1 37/90))- 1 17/60=

17 12/60 - 8 21/60 +  (9 11/15 -(2 6/90 - 1 37/90)) -1 17/60=

16 72/60  - 8 21/60 + ( 9 11/15 - 3 43/90) -1 17/60-=

8 51/60 + (9 66/90 - 3 43/90)- 1 17/60=

8 51/60 + 6 23/90- 1 17/60=

8 153/180 + 6 46/90-1 51/180=

13 148/180=

13 74/90=

13 37/45