Jimmy is on top of a mountain that is +2300 above sea level. But Jimmy's friend is on vacation,and he is scuba diving 2300 feet below sea level.In this situation,0 represents sea level.
-5/8 divided by -3/4 is the same as -5/8 multiplied by -4/3. Multiply the tops to get 20. Multiply the bottoms to get 24. A negative over a negative is positive and you end up with 20/24! :)