Question

How do you find the x intercept of `4x-12=0`?

Answer 1

Replace `y` with `0` (if there is a `y`), then solve for `x`. The `x`-intercept is at `x=3`.

Explanation:

The equation `4x-12=0` is for a vertical line, since (the non-existent) `y` does not depend on `x`. We can solve this for `x` as follows:

`4x-12=0`
`4xcolor(white)- color(white)12=12`
`color(white)4 xcolor(white)- color(white)12=3`

Meaning, for any `y` we choose, we will always get `x=3`. And since the `x`-intercept occurs where `y=0`, we know that value of `y` will also give us `x=3`. Thus, our intercept is at `x=3`.

Here is a graph of the line `4x-12=0`:

graph{4x-12=0.0000001y [-10, 10, -5, 5]}