Answer:
5(a +4) = 5a +20
Explanation:
The average rate of change (m) on interval [p, q] is computed as ...
m = (f(q) -f(p))/(q -p)
For the given interval and function, this is ...
m = ((5a^2 -4) -(5·4^2 -4))/(a -4) = 5(a^2 -4^2)/(a -4) = 5(a +4)
The average rate of change on the interval is 5(a+4).