Right, I should know the answer and I'm ashamed to have to ask for help but this is doing my head in.

Actually trying to use this formula for a spreadsheet but I'm totally flumoxed!

So, if A^X = B/C, how do I work out what X is?

E.g, I know that 1.5^14 = 4379/15, but what if I didn't know that X was 14, how can I work it out?

Thanks!