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

1 Answer
May 17, 2017

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!