Answer :
Answer:
Decay, 60%
Step-by-step explanation:
Remember that the exponential function is written in the form [tex]y=ab^x[/tex]. In this problem, a=57 and b=0.4. A function is considered a growth function when [tex]b>1[/tex]. Since 0.4 not greater than 1, this is an exponential decay function.
Now, to find the rate of decrease we can use part of the form [tex]y=a(1-r)^x[/tex].
[tex]1-r[/tex] represents the percentage decrease, in this case, 0.4. If that entire term is 0.4, we need to solve for [tex]r[/tex].
[tex]1-r=0.4\\r=0.6[/tex]
So, the rate of percentage decrease is 60%.
I hope this helps!