Answer:
The selling price of the puppy is $284.50.
Explanation:
In the present case, the puppy's original selling price is $ 339.50. At this price a discount of $ 55 is made, that is, that amount is subtracted from the original price, modifying the sale price.
Therefore, since 339.50 - 55 results in 284.50, the puppy's sale price goes from $ 339.50 to $ 284.50, taking the aforementioned discount.