Question 195838
Most of the time you are asked to graph a line, that equation will have two variables in it (x and y). In this case, there is only one variable (y).

What this equation is telling you is 'no matter what value I pick you x, the value for y is always -1'.

If you plot any two points with the y coordinate = -1, you can quickly see that the line containing those points is a horizontal line that runs through the point (0, -1).

For a nice tool to help with this type of plotting, go get geogebra. See this URL for a link to some nice tools --> http://collabvsl.wetpaint.com/page/Mathematics+Applications