You can put this solution on YOUR website! If you really have no idea where to start, you should be reading about graphing.
Pick 5 numbers for x. PLug them in and work out y
BTW Since this is a straight line you only need two points. But beginners should plot more points to make sure they are not mixing x's with y's and are plotting them correctly.
I'll get you started
x=0 y=-3
x=6 y=0
x=12 y=3