Question 971813
If one forgets how logs work

log base 10 of 100=2

10^2=100

Do the same here 
25 ^x =125

but 25 is 5^2

(5^2)^x=125
5^2x=125
5^3=125

2x=3
x=(3/2)

25^(3/2)-125

Key is recognizing that 25 can be written as 5^2.