Question

Jeri installs granite counter tops. She charges $400 for all jobs and then $80 per linear foot of granite. • What is the y-intercept on the graph? • What does it represent? • What is the value of the slope? • What does it represent?​

Answer 1

Answers/Step-by-step explanation:

1. Create an equation.

Knowing that the flat fee for jobs is $400, and that the price may increase depending on the linear feet of granite used in the job, the function that gives us the price of a job depending on the amount of granite (linear feet) is the following:

`P(x)= 80x+400`.

2. Y-intercept.

The y-intercept is the point where the graph of a function touches the y axis. It's generated when x is 0. Hence, if we take the equation and substitute x by 0 we get the y-intercept. This is how to do it:

`P(0)= 80(0)+400\\ \\y=400`

Therefore, the y-intercept of this graph is located at the point (0, 400).

3. What does the y-intercept represents.

It tells us that the minimal price of Jeri's job is $400, even if no granite is used on the job.

4. What is the value of the slope?

The slote of a linear equation is always the coefficient of x when the equation is solved for y. In this case, the slope of the graph is 80, since that's the number x is being multiplied by with the function solved for y.

5. What does it represent?

It represent the increase in price that a job has depending on the amount of granite (per linear foot) used on it.