Answer:



Arithmetic sequence
Step-by-step explanation:
We are given that
A(1)=9
We have to find first three terms and identify the sequence is geometric or arithmetic.
Substitute n=1
Then, we get

For n=2

For n=3





When the difference of consecutive terms are constant then the sequence is arithmetic sequence.
Therefore, given sequence is arithmetic sequence.
Depending on the values of 'r', 't', and 'e', the numerical value of that expression
might have many factors.
For example, if it happens that r=5, t=1, and e=4 for an instant, then, just
for a moment, (r + t)(e) = (5+1)(4) = 24, and the factors of (r+t)(e) are
1, 2, 3, 4, 6, 8, 12, and 24 . But that's only a temporary situation.
The only factors of (r+t)(e) that don't depend on the values of 'r', 't', or 'e' ,
and are always good, are (<em>r + t</em>) and (<em>e</em>) .