2.836x10^-5 is going to be your answer
Use the site called Desmos, it's a graphing calculator and should help you in all the ways you need. It isn't complex. Just put that equation in a box and it graphs it for you.
12000 = 2x - 1500
12000 + 1500 = 2x
13500 = 2x
13500/2 = x
6750 = x <=== original price
