The sales price of a car is 12590 which is 20 off the origin

The sales price of a car is $12,590 which is 20% off the original price. What is the original price. I want the explanation of how this is solved. The answer is already on here but there is no explanation.

Solution

Percentage calculations are always done against the original..not the final answer, so lets call the original price x.

20% discount from x is (20/100)x or 0.2x. This discount is taken off the original, x, so we have x-0.2x which is 0.8x and this is the sales price of 12590.

So 0.8x = 12590
x = 12590/0.8
--> x, the original price = $15737.50