Answer:
First, we have to know the discount percentage.
Let's say that is 20% off, this would be in decimal number 0.20.
Now, if the regular price is
, then the dollars discounted are

And the final price is

Which means that the final price is 80% of the regular prices.
Now, for a general case, let's call
the percentage discount, in this case, the final price would be
