Monthly cost for a car problem

[Nitroglycerin]

I hope this is the right place to post a question like this, so I apologize in advance.

I am in desperate need of trying to find out how to set this thing up:

The cost of owning and maintaining a car depends on how much you drive it. According to Time magazine, the monthly cost, in dollars, varies linearly with the miles per month that you drive. On average, the cost if $366 per month for 300 miles driven and $510 for 1500 miles driven.

a) Write an equation giving the monthly cost of owning a car in terms of the miles driven.

b) Predict your monthly cost if you drive 1000 miles.

c) What is the cost intercept?

 

[Mrspi]

I hope this is the right place to post a question like this, so I apologize in advance.

I am in desperate need of trying to find out how to set this thing up:

The cost of owning and maintaining a car depends on how much you drive it. According to Time magazine, the monthly cost, in dollars, varies linearly with the miles per month that you drive. On average, the cost if $366 per month for 300 miles driven and $510 for 1500 miles driven.

a) Write an equation giving the monthly cost of owning a car in terms of the miles driven.

b) Predict your monthly cost if you drive 1000 miles.

c) What is the cost intercept?

Let x = number of miles driven
Let y = monthly cost

Ok...you are GIVEN two ordered pairs:

When you drive 300 miles, the cost is $366. This gives you an (x, y) pair of (300, 366)
When you drive 1500 miles, the cost is $510. This gives you an (x, y) pair of (1500, 510)

Ok...you have two points on the graph. Find the slope, using (y2 - y1)/(x2 - x1)....

Then you can use the point-slope form for the equation of a line: y - y1 = m(x - x1)

Once you've found the equation of the line, you can find the cost (y) intercept, and the monthly cost for any given number of miles.