Question

If y = 2x - 3, then which of the following ordered pairs (1, -1), (-3, 0), (5, 4) lies on the graph?

Answer 1

`(1, -1)` lies on `y = 2x -3`.

Explanation:

To check whether a point lies on the line, substitute either `x or y` into its corresponding equation. If you get the other coordinate correctly from the equation, the point lies on that line.

Let's substitute `x = 1` in `y = 2x - 3`
`impliesy = 2xx1 - 3 = 2 - 3`
`impliesy = -1`
This corresponds to the y-coordinate in (1, -1). Thus the point (1, -1) lies on the given line.

Substitute `y= 0` in the equation.
`0 = 2x - 3`
`implies3 = 2x`
`implies x = 3/2`

For (-3, 0) to lie on the line, putting `y = 0` should have given us `x = -3`. Since it didn't, the point does not lie on the line.

Similarly, (5,4) does not lie on the line. Try plugging in one of the values to see it.
graph{y = 2x -3 [-10, 10, -5, 5]}