Question

How do you graph the equation `3x+y=-1`?

Answer 1

Find values for `x` and `y` then plot the graph.

Explanation:

Start by separating `y` on the left side of the equation. This gives you:

`y = -3x-1`

Next set up plot points. Since this is a linear equation, you only need 2 points. Easy points are the `y`-intersect (the point where `x` is `0`) and `1`.

The `y`-intersect is where `x` is zero so using our equation:

`y = -3(0) -1" "` (substitute `0` for the `x` in the equation)

The `y`-intersect is `-1`. The coordinate is `(0, -1)`.

You need one more point on the graph. We will use `x = 1`. Going back to our equation:

`y=-3(1) - 1 = -4" "` (substitute `1` for `x` in the equation)

This coordinate is `(1, -4)`.

With these two points, `(0, -1)` and `(1, -4)`, you can plot your graph.

graph{(y+3x+1)((x-0)^2+(y+1)^2-0.06)((x-1)^2+(y+4)^2-0.06)=0 [-10, 10, -5, 5]}