Question

How do you find the x and y intercept of `-3x+9y=-18`?

Answer 1

The `x`-intercept is `(6, 0)`
The `y`-intercept is `(0, -2)`

Explanation:

The `x`-intercept occurs when `y` equals zero, and the `y`-intercept is when `x` equals zero.

Knowing that, let's solve for our `x`-intercept by setting `y=0`.

`-3xx x+9xx0=-18`

`-3xx x=-18`

divide by `-3`

`x=6`

The `x`-intercept is `(6, 0)`

Now let's solve for the `y`-intercept

`-3 xx 0+9 xx y=-18`

`9 xx y=-18`

divide by `9` on both sides

`x=-2`

The `y`-intercept is `(0, -2)`

Just to check our work, let's graph the equation and see if our `x` and `y` intercepts match:

graph{-18=-3x+9y}

They match! Good job!