Finding logb397 in terms of A and B

[Suy]

Homework Statement

If Log_b2=A and Log_b49=B, what is log_b397, in terms of A and B.

This is one of the bonus question in my geometric quiz and i don't remember if the number is 397. I wonder if anyone get this?

Homework Equations

The Attempt at a Solution

here is what i did
b^A=2 and b^B=49
b=2^1/A b=49^1/B
49^1/B=2^1/A --> log(49)/log(2)=B/A

because this is geometric quiz, so i assume this one have a geometric
so i use ar^n-1
r : log(49)/log(2)=B/A
a : log(2)

log(2)(B/A)^n-1=log_b397
am i right?

 

[Suy]

sorry wrong post...