There are many ways to graph this,
You could either make table of values and get points in order to plot the graph easily, for this one you basically just plug in values such as -2, -1, 0, 1, 2 into the equation for x. You should get values for y and in turn be able to graph it.
You could also use a much easier method, using the equation, you could first get the y-int, this would be b so that would be one of your point. Then you could do the step method with your slope. RISE / RUN so from the point that you have you go how many units it says you to go, for this one you go 3 units up and 2 units left. If it is negative you should act accordingly.