# How do I find the average rate of change of the function from x1 to x2?

## The function is f(x)= -2x + 15 and x1= 0, x2= 3

The average rate of change is $- 2$.
$m = \frac{f \left(3\right) - f \left(0\right)}{3 - 0} = \frac{9 - 15}{3} = - 2$.
In this case $f \left(x\right)$ is linear, so the average rate of change will be equal to the slope of the line on all intervals.