Answer:
See answer below
Explanation:
Hi there,
First checkbox, Second-to-last checkbox, and last checkbox are all valid expressions.
based on a common algebraic rule

The first checkbox is just the stated answer.
The second-to-last answer is the same, as it can be rearranged as follows:
based on the same algebraic rule above, applies for negative numbers as well!
The last checkbox is simply the definition of an exponent; each exponent has been expanded;

Study well and persevere.
thanks,