How to get coordinates to 2x+y=4 for -2 -1 0 1 2?

Question

How to get coordinates to 2x+y=4 for -2 -1 0 1 2?

2 Answers

Answer Question

Answer 1

If the values listed are those for x and you need to find y, you can solve for y as
2x + y = 4
y = 4 - 2x (subtract 2x)
Your first x value is -2, so y is
y = 4 - 2*(-2) (put -2 where x is in the equation)
y = 4 + 4 = 8
The first pair of coordinates is (x, y) = (-2, 8).

We can do the remaining x values in a list to save a little bit of effort and writing
y = 4 - 2*{-1, 0, 1, 2}
y = 4 - {-2, 0, 2, 4}
y = {6, 4, 2, 0}

The remaining coordinate pairs are
(-1, 6), (0, 4), (1, 2), (2, 0)

Answer 2

There's a shorter way, that is to find the x- and y-intercept:

1. To find x-intercept, let y be 0.
2x=4
x=2, so x-intercept is at (2,0)

2. To find y-intercept let x be 0.
Y=4, so y-intercept is at (0,4)

The purpose of finding the coordinates of a line is to plot the line. No need to do multiple solutions. Just plot the x- and y-intercept, then connect...:)