Question 476520
{{{ log ( 7,(x+8) ) - log ( 7,(x-5) ) = log ( 7,4 ) }}}

==>{{{ log ( 7,((x+8)/(x-5)) ) = log ( 7,4 ) }}}

==>(x+8)/(x-5) = 4, because the logarithmic function is 1-to-1.

==> x + 8 = 4x - 20 

==> 28 = 3x

==> x = 28/3.

This value satisfies the original equation, and so is the final answer.