We have to convert 2% in to a decimal then multiply it into the x-value which is the months with the addition of 500 because that is the start value.If you were to graph this it would be a linear fuction, y=0.2x+500. The rate of change is found by slope, so rise over run. taking 2 points on the graph and do this (y 2-y 1)/(x 2-x 1) and graph the equation and get two of the points and find the slope for the rate of change.
