This is a problem with multiple parts. When you complete a part and are told that your answers are correct t then click to go on to the next part and resubmit your answer. When you do this ignore the statement that there are unanswered questions and just answer the new questions.

When you first saw exponents they were positive integers.
They counted the number of copies of the base that were to be multiplied together.
For example, $5^3 = 5\cdot 5\cdot 5=125$.
You can refresh your memory by calculating a few examples:

$7^2=$

$3^5=$

If someone asked you to compute $3^0$ or $9^{\frac{1}{2}}$ your reaction would be that the question is ridiculous
because you can't multiply no threes together nor can you multiply a half of a nine together,
and, based on what you have been taught so far your reaction would be totally reasonable.
But mathematicians have found things like $3^0$ and $9^{\frac{1}{2}}$ to be useful
and they used a very important technique to find a reasonable way to deal with them.
Since this method will arise in several topics you will study in middle and high school,
we will explain it in detail.

The trick is to find an explanation other than
" the number of copies of the base to multiply together" for the exponent
in such a way that it will give the same result on the things we already know
and enable us to use exponents that are not positive integers.

Suppose we let the positive number $b$ be the base and make the following definition:
Rule 1: $b^1=b$
Rule 2: $b^{n+1}=b^n\cdot b$

This definition must look strange to you so let us use it to find $5^3$.
The base is $5$ so we can use Rule 1 to say that $5^1=5$.
Now that we know what $5^1$ is we can use Rule 2 to say that $5^2=5^{1+1}=5^1\cdot 5 =5\cdot 5=25$.
Next we can use Rule 2 to say $5^3=5^{2+1}=5^2\cdot 5 =25\cdot 5=125$.
This is much uglier than just saying that $5^3=5\cdot 5\cdot 5$. But now we can do some neat tricks with it.

Notice that in Rule 2 we did not say that n had to be a positive integer. So we will use the definition
to find out what $5^0$ has to be. But you can do some of the work.

We know from rule 1 that $5^1=5$. From Rule 2 we can say That $5^{0+1}=5^{0}\cdot 5$.
Now if $5^0$ is a number which multiplied by 5 gives us $5^{0+1}$ then we know that $5^0$ =