When you graph it will look like the picture.
1. It's in slope-intercept form (y=mx+b) meaning that 3=m and -1=b. m is the slope of the line, ie: how it moves. And b is the y-intercept, where it crosses the y-axis.
2. Next, Plot the y-intercept which in this case is -1. It will be plotted at the point (0,-1)
3. Next you find the slope which in this case is 3, which means the slope is 3/1. When understanding slope you need to know that the numerator is the rise (how much it goes up or down) and the denominator is run (how much it moves to the left or right).
4. Start at the y-intercept and follow the slope, so up 3 right 1. and repeat this process. Since the slope is positive it will go to the right.
5. Once you've graphed all you could to the right go back to the y-intercept and do the opposite of the slope and go down 3 left 1. once you've followed these steps you have graphed the line.