From the graph, you can first see that there is a positive slope, and a negative y intercept. That should automatically rule out the first option.next, find the slop...
To do this take the two points that are given (2,5.5) and (5,15.25) and do rise over run. This would be (15.25-5.5)/(5-2). I just put this in a calculator and found the slope to be 3.25. You automatically know the answer because the only equation with the slope 3.25 is the third one.
