Dollar City is having an end-of-year sale, and all prices are being slashed. On the graph below, the x-axis represents the old price, and the y-axis represents the new sale price, in dollars.
Not to be outdone, Penny World, whose manager was a math major, has announced that all sale prices (S)
will be determined according to the equation:
S = (0.15)P
where P is the original price.
Which store's sale is better?
o