I have this simple exponential equation:
3^(x+2) + 3^(x-2) = 246
It is easy to see that the sum must be 243 + 3 = 3^5 + 3^1 and therefore x = 3.
But I haven't been able to solve it in the conventional way, using logarithms or some other method. Do you have any ideas to offer? Many thanks.