The expression for the average rate in change is :
[tex]\text{ Average Rate =}\frac{y_2-y_1}{x_2-x_1}[/tex]
In the graph consider any two coordinates : (2, 1) & ( 1, 3)
Substitute the coordinate :
[tex]\begin{gathered} \text{ Average Rate =}\frac{y_2-y_1}{x_2-x_1} \\ \text{Average rate = }\frac{3-1}{1-2} \\ \text{Average Rate=}\frac{2}{(-1)} \\ \text{Average Rate=-2} \end{gathered}[/tex]
Average Rate = -2
