Since the equation is in y=mx+b form or slope-intercept form, you graph this equation based on the slope and its y-intercept. Note how m is the slope and b is the y-intercept. Now, since your b is equal to -2, that is the value at which your line will intercept or cross the y-axis. Now, you just have to focus on your slope, which is 1/2. Since a slope is represented by many things, one thing being the rise over run or something (rise/run), then you know that the slope of 1/2 has a rise of 1 and a run of 2. This teaches you how to graph the equation, because after plotted the point of the y-intercept on the graph, you "rise" or go up by 1 and then you "run" or move horizontally by 2 grid squares. This is what you will do for every point on this line, which you may plot. I hope this helps.