Well to find this answer, we will have to find a common denominator for each fraction so it will be easier to subtract.
9 is a common denominator for both numbers since both denominators, 9 and 3, can go into 9. We don't have to change 2/9, but we will have to change 1/3.
Multiply 1 and 3 by 3 to get our new fraction 3/9.
2/9-3/9= -1/9
So our answer would be - 1/9. Hope I helped!