Ahummer four-door costs $57915. a dealer has a 12.3% markup. what is the selling price of the vehicle?

For $57915 being what the dealer buys it at:

(57915)x(0.123) = 7123.545
(57915)+(7123.545) = 65038.545

For the $57915 being the final selling price:

(57915)x(0.123) = 7123.545
(57915)-(7123.545) = 50791.455

Ya i could just need to know what type of math