22/23-18/23+5/23, 8 7/9+(7 5/9 -4 4/9), 11 2/19-(3 17/19+6 14/19)

22/23-18/23+5/23=9/23
8 7/9+(7 5/9-4 4/9)=8 7/9+3 1/9=11 8/9
11 2/19-(3 17/19+6 14/19)=9/19
1)3 17/19+6 14/19=9 31/19=10 12/19
2)11 2/19- 10 12/19=10 21/19-10 12/19=9/19