A)
Part 1:
We can use the exponential rule shown below:

when same bases are multiplied, the exponents are added
Thus,

Part 2:
We can use another exponents rule:

Now, we can write 5^ -1 in another form:

One fifth is a fraction that is definitely above 0 and less than 1.
Thus,
This is a value between 0 and 1.