Answer:
See below
Explanation:
Consider the 4th step. It is true that 25 = 5 * 5, and thus is equivalent to 5^x, but doesn't necessarily mean that x = 5. Instead, you could rewrite 5^x = 25 as 5^x = 5^2, and with a similar base of 5, the exponents would have to be equal, and thus x = 2;

Hope that helps!