Using exponential function concepts, it is found that it represents a decay of 0.9%.
<h3>What is an exponential function?</h3>
A decaying exponential function is <em>modeled </em>by:

In which:
- A(0) is the initial value.
- r is the decay rate, as a decimal.
In this problem, the function is:

Hence:


Thus, it represents a decay of 0.9%.
You can learn more about exponential function concepts at brainly.com/question/25537936
The 18th month he will have to change both,
I hope this helped!
5 times a number subtracted from 3.
Hope this helps!
<span>1 hundreds + 5 tens + 12 ones
= 100 + 50 + 12
= 162</span>