What is the value of this expression 1/5^-5

So for negative expressions, say, - x ^ - y, it just equals 1/x^y.

So in the case of fractions, you can just flip the fraction, and then just do it to the power of y.

So here, 1/5 flipped is 5/1, to the power of 5.

5 ^ 5 is 3125.

3125 is your answer ..., ...