Answer:
The difference between slope and y-intercept, is y-intercept is a specific point. Y-intercept is when the line crosses the y-axis, or when x = 0. Slope is how much the y value changes when the x has changed +1, or -1, if that makes sense.
I was gonna do an example, but I got lazy, hehe.
total surface area Stot = 1180 in2
lateral surface area Slat = 920 in2
top surface area Stop = 130 in2
bottom surface area Sbot = 130 in2
So you need to find the slope and the y- intercept. So, the slope is always the coefficient on the x. In this case it is 4. The y-intercept is the other number. In this case it is -5. So the slope is 4 and the y-intercept is -5. On your graph (the y axis) find -5. Then you go up 4 and to the right 1 because of four were a fraction it would be 4/1. Keep going up four and right one a couple times. Then reverse it. Go down 4 left 1. That as a fraction would look like -4/-1. Then connect your points and make it a line!
Hello! :)

9 = (3/8)y
Solve for y.
Isolate y by dividing both sides by 3/8, or multiplying by its reciprocal (8/3)
9 · (8/3) = (3/8)y · (8/3)
72 / 3 = y
y = 24