Question 685572
The trick is to use {{{ log(5,25) = 2 }}}, then
{{{ log(5,(x+7)) + log(5,(x-7)) = 2 }}}
{{{ log(5,(x+7)) + log(5,(x-7)) = log(5,25) }}}
{{{ log( 5, (x+7)*(x-7) ) = log( 5,25 ) }}}
{{{ log( 5, x^2 - 49 ) = log( 5,25 ) }}}
{{{ x^2 - 49 = 25 }}}
{{{ x^2 = 74 }}}
{{{ x = 8.6023 }}}
( There is a negative solution, too, but I can't use it
since that would give me log( 5, negative number ) ,
and there is no log to a positive base that can give 
me a negative number.
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check answer:
{{{ log( 5,(8.6023+7)) + log( 5,(8.6023-7)) = 2 }}} 
{{{ log( 5,( 15.6023 )) + log( 5,( 1.6023 )) = 2 }}} 
{{{ log( 5, 24.9996 ) = 2 }}}
I think the error is due to rounding off