Question 314692
The y-intercept is the point where x=0.  So, if x=0, then plug it in to the formula, 
y+x=-9
y+0=-9
y=-9


That was easy, right?  So to get a second point, do the same thing for the x-intercept.  Let y=0, and find x.
y+x=-9
0+x=-9
x=-9


Graph these two points, and connect the dots.  The graph should look like this:
{{{graph(300,300,-10,10,-10,10, -x-9) }}}


For additional explanation on GRAPHING, please see my own website.  Click on my tutor name "rapaljer" and then click on the link that is given there.  From my Homepage, look for the link "Basic, Intermediate, and College Algebra: One Step at a Time."  Select "Basic Algebra," and look for "Chapter 5".  There are several sections at the beginning of this chapter that explain graphing.  These sections include my own explanation written especially for students who may have trouble understanding these skills, examples, exercises, and ALL the answers.  Many of the exercises are solved in detail on the "Math in Living Color" pages that go with these pages.


I also have some videos from my own classes from a few years ago. These videos can now be viewed on-line FREE.  To see the videos, from my Homepage, find the link "Rapalje Videos in Living Color," choose "Basic Algebra" and look for the video "Graphing and Slope of a Line."   


Dr. Robert J. Rapalje, Retired
Seminole State College of Florida
Altamonte Springs Campus