Question 15044
The equation x+y=4 is in what is called "standard form" where you have an x term plus (or minus) a y term = a number term.  When this happens, I think the easiest way to graph it (usually) is to graph the two easiest points that you can, the x and y intercepts.  The first points is found by letting x= 0 and find y (that would be the y-intercept!).  Second point is found by letting y=0 and find x (that would be the x-intercept!).


In this case, if x = 0, y = 4.
If y=0, then x = 4.  


Plot these two points: (0,4) and (4,0).  Connect the points with a line, and continue the line in both directions.  It should look like this:

{{{graph ( 300, 300, -10, 10, -10, 10, -x+ 4) }}}


R^2 at SCC