In order to find this, we must first find the slope. We can do that by using the slope formula. For this, we will use the points given of (8, 0) and (0, -2)
m(slope) = (y2 - y1)/(x2 - x1)
m = (0 - -2)/(8 - 0)
m = 2/8
m = 1/4
Now that we have the slope, we can use that and either point in point-slope form to find the equation.
You're going to want to take the total, which is $353.00 and subtract the initial cost, which is $84.00, the number now should be $269. Using that total divide it by $68.00, there you should find your answer of about 4 hours. The precise answer is 3.99588235. But you would round that to 4 hours.
