The question is...

Residents of the town of Maple Grove who are connected to the municipal water supply are billed a fixed amount yearly plus a charge for each cubic foot of water used. A household using 1000 cubic feet was billed $50, while one using 1600 cubic feet was billed $75.

Some how, I came up with the formula...

C(w) = 24x-200, but it does the opposite of what I want it to do... (you put the amount of dollars in as x instead of the amount of square feet, and it tells you how many square feet the amount of money is worth instead of telling me how much money I would need for x amount of square feet...)

For example...

C(50) = 24(50)-200 = 1000

I need...

C(1000) = formula = 50

I tried inverting it, but it made the problem all funky and didn't work

so I said...

C(w) = w/24+200

I don't know if I inverted it wrong, or if something is just off with my formulas.