The answer is:
y= -2.5x + 4
You have to do -2.5 times the x value
Then add 4 and you should get the correct number for each y value.
Discount, as you are lowering the item price from 100% (Default ) to 75%
Discount = 100% - 75% = 25%
If it was required to find the discount.
discount = 0.25 x Price.
newPrice = 0.75 x Price
Original price = Discount + new Price.
