Simplify the numerator and denominator first:
5/8 + 3/4 = 11/8
-2/3 - 5/6 = -3/2
Now you have 11/8 / -3/2
When dividing two fractions change division to multiplication and flip the second fraction over:
11/8 x -2/3 = 11 x -2 / 8 x 3 = -22/24
-22/24 reduces to -11/12
The answer is -11/12