When we are solving this type of Questions which includes two operations, first we have to go for division then after addition.
(8/9) + (5/6)
6
8/9+5/6 is 31/18.
5/6+1/9=51/54
7/9+5/6 = 29/18
5/9 + 1/6 is 13/18
The sum of 5/6 and 4/9 is 1 5/18
1.388888888888889
6/5 + 2/-9 = 44/45
4/9
9/10
9 + 9 + 9 + 1 + 6 + 5 = 39