Answer:
[tex]f(x)=-9(2)^(^x^-^1^)[/tex]
Explanation:
First, we find the common ratio by dividing any term by its previous term. We should do this a couple of times to make sure it's consistent. In this case, our common ratio is 2. Our first (or 1th) term of the sequence is -9, so our formula becomes
[tex]f(x)=-9(2)^(^x^-^1^)[/tex].