Easy peasy
the average rate of change in section A is the slope from (1,g(1)) to (2,g(2))
the average rate of chagne in section B is the slope from (3,g(3)) to (4,g(4))
A.
section A
g(1)=4(3)^1=12
g(2)=4(3)^2=4(9)=36
slope=(36-12)/(2-1)=24/1=24
section B
g(3)=4(3)^3=4(27)=108
g(4)=4(3)^4=4(81)=324
slope=(324-108)/(4-3)=216/1=216
section A has an average rate of change of 24
section B has an average rate of change of 216
If you use/make a number line, then you will see that the answer is -18 or a. When using a number line, negative = ← and positive = →.
