I can't tell whether you mean this
or this
I'll assume you mean the first way, because the
second interpretation requires iterative methods
or a graphing calculator.
then since the bases are positive and equal
and not equal to 1, then we can just equate
the exponents:
----------------
But if you mean
Then it cannot be solved with algebra or logarithms.
If you have a TI-83 or 84,
Press Y=
Make the first two lines read like this:
\Y1=5^(6X)
\Y2=5^(7X)-6
Press ZOOM
Press 6
Press 2ND
Press TRACE
Press 5
Press ENTER
Press ENTER
Press ENTER
Read at bottom of screen
X=.25553448
Round to three significant digits:
X=0.256
Edwin