I have to assume that your "h" is a variable and that this variable has the coefficient (3/4). If I'm wrong, correct me!
Then (3/4)h - 12 = 8 5/8, or
(3/4)h = 12 + 69/8 The LCD here is 8. Mult. all terms by 8.
6h = 96 + 69 => 6h = 165. Then h = 165/6 (Can't be reduced, but
can be written as 27 1/2)