Question

How would I graph this function: f(x) = 490 – 2/3x

Answer 1

I'm not sure but I think first you have to set values for x (i.e. -1, 0, 1, 2, 3) and substitute each value to the given f(x)

Answer 2

Then solve it to find the f(x) a.k.a the y. You might want to make a table so it would be easy.

I hope this answers your question

Answer 3

Step 1: Find the x and y intercepts. In terms of points they will look like this (x,0) and (0,y). (You have to find the values of x and y)
Step 2: Plot the points on an xy plane.
Step 3. Draw a straight line through the points.

Answer 4

I don't know how to find these points you speak of.

Answer 5

The points are the values you use in your quadrants. It is in the positive and negative axes.

Example
X | Y
-1| (substitute -1 in the f(x))

The result will be the points

Answer 6

So, in f(x)=490-2/3x, I have to substitute -1, 0, 1, 2, etc, to find the points?

Answer 7

Yes

Answer 8

So then.. f(-1)=490-2/3x would be a start to finding these points?

Answer 9

Yes, but you also shouldn't forget about the other x.

The answer that you get from substituting will be the y-intercept. Which means that f(x) is equal to y.

To plot the points you will be needing the value of x that you used for x-intercept and the y-intercept

Answer 10

Right. I'm even more confused than when I began. Maybe I'll just get a job at McDonalds once I fail school.
Have a medal anyhow for your effort, thanks!

Answer 11

Oh hey, that's not a good way of thinking. We can finish this. What are you confused about?

Answer 12

Everything pretty much. I did get the art of substituting numbers for x out of the function, but after that I'm not sure what's going on.

Answer 13

Part*

Answer 14

What happens if you let x = 0, then solve for y as follows:

y = 490 - (2/3)*(0)

Answer 15

You only need two points two create a graph of a line btw. Through any two points exists exactly one line.

Answer 16

f(x) is a linear function as you already know.

Answer 17

Oh okay. You substituted: f(x) = 490-2/3x with -1 for x.

f(-1) = 490-2/3(-1)

Then you solve that and you get the y

Since there is 2 valuse needed to plot a point in the quadrants you'll need the x and y.

To plot points, find -1 then the value of y

Answer 18

What @Hero said is right

Answer 19

Okay, so substituting for x gives you the y?

Answer 20

Pretty much, yes

Answer 21

So how do I then find the other point I need to graph the line.

Answer 22

You put another value for x

Answer 23

I don't understand, if substituting for x gives you y, then why do it twice. I thought to create a line you need both x an y, not y and y.

Answer 24

You do it twice so you get two points. And as hero said you only need two to create a linear graph

So if you have -1 and the y then you get 1 point. If you take 3 or whatever value you want for x and solve for y, then you get another.

Answer 25

They are partners, you see. There should be (x,y) for 1 point. The x and y are called intercepts

Answer 26

Ohhh, I see.
I may not fully comprehend but I think I can do it. Only a little more school left anyways, then I'll never use any of this again in my lifetime.
Thanks once again!

Answer 27

No problem! I think you'd do great!