Question

I’m trying to graph for example, questions like; 3x + y = -1, and finding the x-intercept but I’m not understanding how to do it

Answer 1

We have the following function:

`3x+y=-1`

First, We leave the function in the form of the equation of the line y=mx+b.

`y=-3x-1`

Now we pick two random points to replace in the function.

We use x=-2 and x=1 remember, these points can be anything, not necessarily these.

Now we solve x=-2 and x=1

`\begin{gathered} x=-2 \\ y=-3x-1 \\ y=-3(-2)-1 \\ y=6-1 \\ y=5 \end{gathered}`
`\begin{gathered} x=1 \\ y=-3(1)-1 \\ y=-3-1 \\ y=-4 \end{gathered}`

The points are:

`\begin{gathered} (-2,5) \\ (1,-4) \end{gathered}`

Second, with these points, we draw a line between these two points, so we can describe the line of the line function.