You need to find the slope of the line and the y intercept, you can do this by plotting the points into a graph and figuring it out that way, or you can use the equations y2-y1/x2-x1 (for slope) and y=(*the slope from the other equation*)x+b. For both equations plug in a corresponding x and y coordinate given on the list (y1 and y2 would be consecutive coordinates, so 1 and 2, and same for x1 and x1, so -9 and -13). You should get (-4/1) for the slope, and when you plug that into the other equation you should get 5. Lastly you plug all these numbers into y=mx+b, and you get your answer.
5 meters/ 1 second because if you 40 and 8 you will get 5 and divided 8 by 8 and you get 1, you just divide the denominator by both numerator and denominator.