The answer would be eleven eighths over negative nine sixths

Ok so to add and subtract fractions you need to find a common denominator. But first, we need to go one step at a time. Lets start at the top. The common denominator of 5/8 and 3/4 is 8. So multiple 3/4 by 2 on top and bottom. Now we have 5/8 + 6/8. Now we just add the numerators and that gives us 11/8. Great! We can move onto the bottom now. The common denominator of -2/3 and -5/6 is 6. You might be asking why I said -5/6 and not 5/6, the reason is because subtraction is the same as adding a negative number. You may or may not already know that, but I just wanted to be as clear as possible. So multiply -2/3 by 2 on top and bottom to get -4/6. Now we add the numerators of -4/6 and -5/6. So -4+(-5) which is the same as -4-5 and that equals -9. But there's more! -9/6 simplifies to -3/2. Awesome! Now we have our two fractions, we need to divide them. When it comes to fractions, division is the same as flipping and multiplying. So first we need to flip. 11/8 / -3/2 is the same as 11/8 x -2/3. Now we just multiply straight across and the answer will be -22/24 which simplifies to -11/12. And that is our answer! I hope you understand and I hope that my answer is correct. I did all of that in my head while typing so I might have made some mistakes. Please leave a good rating and thanks. Thank you and have a nice day!