Need help with a formula

I am trying to do the reverse of what I have attached. This is a very basic set of formulas that start with a base premium, then add in a state tax that is the base premium + 2 fees (they can vary every year) multiplied by a set percentage. Then do the exact same with a second percentage (another tax) of the base + the 2 fees. I can input the base premium and come up with the final every time with no issue. What I am trying to do is the exact opposite, start with the final number (including all fees and taxes) and let it tell me what each percentage is, and ultimately the base premium. It will save a ton of time trying to back into numbers to get the final desired outcome. 

Any help would be greatly appreciated. I am by no means an excel wizard (obviously) but do better than most.

Thanks