A new car has a list price of $31,500. Suppose that the dealer markup on this car is 10 %. To determine the dealer's cost for the car, solve the equation x+0.10x=31,500 where x represents the dealer's cost for the car before markup.
The answer to your question is really simple just take $31,500 and subtract 10%. The initial price would be $28350. Unless you need it to be solved the other way in which it would be 28636.363636.