Question 54011
I'm assuming you have a typo in your first equation and it should be y=3x.  The second equation, when solving for y, becomes y=-x+4.  Now just create some ordered pairs for each equation, plot those points and connect with a straight line -- be sure not to confuse which points belong with each line.  The graph is:
{{{graph(200,200,-5,5,-5,5,3x,-x+4)}}}.