Answer:
112 $ is the original price
Step-by-step explanation:

you have to think that the original price multiplied by 0.75 (also known as 75%) gave the result of what he saves i.e 84 $. So we put up an equation with the original price multiplied by 75% which equals the 84 $ he saved on buying that item on sale
Mark points (0,0), (-1,-1), (1,-1), (-2,-4), (2,-4)
First place is a
Fifth place is b
Negative 72.75 is your product. It is very simple once you understand it.