Question

How do you graph `9x-3y=-9` using the intercepts?

Answer 1

See below:

Explanation:

When using intercepts, remember that the the `x`-intercept will be in the form of `(x,0)` and the `y`-intercept will be in the form of `(0,y)`, where the `x` and `y` in the points are the intercepts.

We can use this to find the intercepts in our equation `9x-3y=-9`.

x intercept

Set `y=0`:

`9x-3(0)=-9`

`9x=-9`

`x=-1 => (-1,0)`

y intercept

Set `x=0`

`9(0)-3y=-9`

`-3y=-9`

`y=3 => (0,3)`

Graph

Let's plot those points:

graph{((x+1)^2+(y-0)^2-.5^2)((x-0)^2+(y-3)^2-.5^2)=0}

and now connect them up:

graph{((x+1)^2+(y-0)^2-.5^2)((x-0)^2+(y-3)^2-.5^2)(9x-3y+9)=0}