Answer:
The rate of change is 3.
Step-by-step explanation:
When the y vaues increase, they add 3 three times.
a(x)= [tex]\frac{f(b)-f(a)}{b-a} \\[/tex]
a(x)= [tex]\frac{12-9}{3-2}[/tex]
And If you use this for all the numbers, the value would be three.
