you have to solve for x first.
\(log_{25}(x-4)=0.5\\ \text{can be rearranged as }\\ x-4=25^{0.5}\)
you can take it from there.
Just remember that the LOG of something is a POWER.
I just remember this and then I do my other rearrangements the same way
\(10^2=100\)
\(log_{10}100=2\)