First you do 2/3h-1/3h. Then you -11 on both sides, so you can get 11 to the right side. After that times 3/1 on both sides, so you can get 1/3 to the other side. The answer would be -9.
2/3h-1/3h+11=8
1/3h+11=8
1/3h+11-11=8-11
1/3h=-3
1/3h x 3/1=-3 x 3/1
h=-9