# How would you create a (x,y) table for the equation y=2x-1?

Nov 7, 2014

To crate an $\left(x , y\right)$ table for $y = 2 x - 1$, you could plug in a bunch of $x$ values into that equation and find the corresponding $y$ values and then tabulate the results. This will give you an idea of what the graph will look like. Note that the graph of $y = 2 x - 1$ is a line that goes on forever and ever in the $y$ and $x$ directions, but by plugging in a few values of choice, you can see a certain part of the graph and then put arrows on the endpoints you get to indicate that the line continues.

So to make a table, you have to pick a few values to plug in. I think that 5 values would be good to start with. Let's say those values are

$x = - 4 , - 2 , 0 , 2 , 4$

Note that you can pick any values you want. I just picked these because they're easy to work with.

So,

$x = - 4 , y = 2 \left(- 4\right) - 1 = - 9$
$x = - 2 , y = - 5$
$x = 0 , y = 2 \left(0\right) - 1 = - 1$
$x = 2 , y = 2 \left(2\right) - 1 = 3$
$x = 4 , y = 2 \left(4\right) - 1 = 7$

You can then tabulate these values with x and y as headings, and whatever inputs you choose under x, and whatever outputs you get under y. It can look something like this:

x -4 -2 0 2 4
y-9 -5 -1 3 7

You can then plot these points to see what the graph will look like. The corresponding points are (-4, -9), (-2,-5), (0,-1), (2,3), and (4,7)
The graph of $y = 2 x - 1$ looks like this: 