Lynn found, for $ she driven  miles in May and for $ she driven  miles in June.

The monthly cost depends on the number of miles she travels.

(a)

The monthly cost  and distance driven  are linearly related.

Find the monthly cost  as the function of distance driven .

Here  is the input variable and  is the output.

From the data the two points are  and .

The line equation passing through the points and  is .

Substitute  and  in the line equation.

The linear equation is .

(b)

Find the cost if she driven a  miles per month.

The distance driven is  mi.

The linear equation is .

Substitute  in the linear equation.

Lynn driven a  miles per month it cost  $.

(c)

Graph :

(1) Draw the coordinate plane.

(2) Draw the linear equation .

axis : Distance driven as .

axis : Monthly cost .

From the graph, slope is 

The slope represents that  miles cost is $.

(d)

The linear equation is .

intercept represents the fixed cost of the cost function.

Here intercept is  and it represents that Lynn pays $ in a month before she drives the car.

(e)

The change of cost per mile increases linearly at a constant rate.

(a) The linear equation is .

(b) Lynn driven a  miles per month it cost  $.

(c) Graph of the linear equation  is

The slope represents that  miles cost is $.

(d) intercept represents the fixed cost of the cost function.

(e)The change of cost per mile increases linearly at a constant rate.