Me. would prefer picture added or not. will give you !

Remark

I'm going to get the graph for this first. The easiest and best tool for this sort of thing is Desmos. The graph will tell you which points to plot.

Formula Development

You start out with the cost being 60 dollars. He ALWAYS has to pay this. Then for every mile he drives, it costs 0.75 dollars (75 cents). So the y axis is the total amount of money he has to pay, and the x axis is what he pays per mile. The y intercept is 60, and the x function is 0.75x

y = 0.75x + 60

Solution

If you set up a table using the graph, you could see 5 points clearly.

x               y

0              60

20            75

40            90

60            105

80             120

===========================

35

y = 0.75x + 60

y = 0.75*35 + 60

y = 22.5 + 60

y = 82.5

20 is on my chart.

Just plot these points (on a separate sheet of paper and use a ruler). Just follow the even spacing of the graph enclosed.