Question

Jackson pays $18 per month for his phone service, plus $0.07 for each long distance minute used. Which of the following correctly describes the y-intercept?

Answer 1

The equation is y= 007x +18

To find y-intercept we replace x by 0; so y= (0.07)(0) +18 Hence y =18

Answer 2

The y-intercept is:

(0,18)

Explanation:

It is given that:

Jackson pays $18 per month for his phone service, plus $0.07 for each long distance minute used.

Let t be the long distance minutes used.

Let 'C' be the cost function that calculates the cost of the phone service.

This means that we an form a liner equation that models this situation as:

C=18+0.07t

Let the cost function is represented by the y-axis and the time i..e number of long distance minutes is represented on the x-axis.

Now we know that y-intercept is a point on the y-axis where x-value is zero.

i.e. here t=0.

When t=0 we get:

C=18.

Hence, the y-intercept is:

(0,18)