Point Generator(based on time)

I have been trying to search for a solution on this problem myself, I have an assignment to make a game based on habitants(x in the formula) which you can buy buildings and some being able to generate points per X amount of time. Preferably I want the variables A B C and time to be blank.

I want to determine the points with the following formula: (A/(-x-B))+C=int y which is based on time. For example, a hotdog stand with the formula ((8000/(-x-63))+50) will generate between 1 and 50 points per hour depending on the amount of habitants(minimum of 1 point is reached at 100 habitants(which makes the hotdog stand available for purchasing) and a maximum of 50 points is reached 15000-ish habitants)

Now I have tried using this formula by altering some existant point scripts(like points on destroy gameobject), but this has not succeeded.