We must find the slope of the line in the graph. In the graph we have two points with coordinates:
We must compute the slope using the rise/run counting method. This method consists in:
1) Subtract the first X-axis point from the second one to calculate the run. In this case:
2) Subtract the first Y-axis point from the second one to calculate the rise. In this case:
3) Divide the rise by the run to calculate the slope m:
Answer: -2/3