Question 64366
log(base 5) 25=x 
Therefore, 5^x=25
Then 5^x=5^2
So,  x=2
---------------
and 
log(base 5) (5)^-2 = x
Therefore 5^x=5^-2
So x=-2.
--------
Hope this makes sense to you.
Cheers,
Stan H.