15% off $32.50 means a reduction of 15% x 32.5 = $4.875 And the paid cost is 32.5 - 4.875 = $27.625
Another method: the discount is 15% of te 100%, that means he will be only 85% (100% - 15%) of the 32.5,, then the paid price will be 32.5 x 85% or 32.5 x 0.85 = $27.625
Because the slope is 0, it means its a horizontal line. because the horizontal is on 3, then it doesnt matter what x is as long as y is 3 if that makes any sense.