Question

A telephone plan consists of monthly fee $15 plus 20 cents per minute for long distance calls made. Write an equation for the total monthly cost C when N minutes are used for long distance calls Graph the equation and find out the monthly cost if 20 minutes of long distance calls are made.

Answer 1

Given:

$15 monthly fee

20 cents per minute for long distance call

Write an equation for the monthly cost C when N minutes are used for long distance call.

From the given data, it is stated that 20 cents are used per minute of long distance calls, we can rewrite this expression as 0.20N.

Next, there is a monthly fee of $15, therefore 15 is constant every month. If we combine these, we can write an equation that goes by

`C=0.20N+15`

Next, to graph the equation, we will first find the cost if:

N = 0

N = 20

N = 0

`C=0.20N+15`
`C=0.20(0)+15`
`C=15`

(0 , 15)

N = 20

`C=0.20N+15`
`C=0.20(20)+15`
`C=4+15`
`C=19`

(20 , 19)

Now, we will just plot these points and we will now have the graph.