Easy exponential equation but don't know how to solve properly.

Hi,

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.

Quote:

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Originally Posted by freighter

Hi,

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.

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Thanks, it's clear for me now :)