Slope is written rise over run. To figure out the slope, the easiest way is to pick two points on the line. There are already two visible points, so we will use those. If you go up 6 and left 4 on the graph from the bottom point, you can find both of the points. So currently, the slope is -6/4. This can be simplified to the final answer, which is -3/2.
Allen has already run 3 hours and will run x amount more to finish. This is 3+x. He must finish under or less than 5.5 hours. So 3 + x < 5.5. You solve and find x < 2.5.
