Here is one way to do it. See the attached image.
Answer: III. y = x^2 - 2x - 48
The y intercept are the points on the graph where the curve hits the y-axis, so it’s the point where x=0
With the equation y=x^2 - 2x - 48 we can easily plug in 0 for x and see that the when x is zero, y is -48.
7 hours because 1 load = 1 hour so 7 loads = 7 hours
12563 is the correct answer