Answer:
x = -9
Explanation:
25^x = 125 ^(x+3)
Rewriting
5^2^x = 5^3^(x+3)
We know a^b^c = a^(b*c)
5^(2x) = 5^(3(x+3))
5^(2x) = 5^(3x+9)
The bases are the same so the exponents are the same
2x = 3x+9
Subtract 3x from each side
2x-3x = 3x+9-3x
-x =9
x = -9