The average rate of change is the distance between y values divided by the distance between x values. We know this as rise/run or slope for linear equations. For non-linear equations, we calculate the average over an interval.
This function has y-values of -1 at x=0 and 5 at x=2.
We add -1+5=6 and divide this by 2-0=2.
6/2=3.
The y-values on average change 3 units for every 1 unit of the x-values.
