Answer:
Average Rate of Change = -0.4145
It means that the amount of CO2 emitted per year will decrease by an averaage rate of 0.4145 (tons - gallon of gas)/mile
Explanation:
In order to solve this problem, we can make use of the Average Rate of Change formula, which looks like this:

So we need to start by finding what A(25) is equal to, so we get:

so
A(25)=7.4875
next, we can find A(20)

so we get:
A(20)=9.56
so now we can use the average rate of change formula:


ARC=-0.4145
and It means that the amount of CO2 emitted per year will decrease by an averaage rate of 0.4145 (tons - gallon of gas)/mile