If you look at my last post, you'll see that I "broke up" the first equation into two seperate equations. If you sketch the graph, it'll look like a v.
You can see that this is a linear equation of the form , where is the slope of the line, and is the y-intercept.
You can use the y-intercept along with the slope of the line to sketch the graph. Or you could use the y-intercept along with another point (ie (1,-4)) to draw the graph. Either way is fine.