I read this as:
(log(25)-log(125)+½log(6252))/(3log(5)).
25=52, so log(25)=2log(5); 125=53, so log(125)=3log(5); 625=54, so log(625)=4log(5) and log(6252)=2log(625)=8log(5).
The problem can be rewritten:
(2log(5)-3log(5)+4log(5))/(3log(5))=3log(5)/(3log(5))=1.
So the solution is 1.