Something to remember is how to multiply terms with same bases, but different exponents:

Essentially, we add the exponents.
Using the information above, we can find our answer:

Our answer is
, or A.
Answer:
C 9i
D -9i
Step-by-step explanation:
sqrt(-81)
sqrt(81) sqrt(-1)
we know that sqrt(-1) = i
±9i
See picture reply for your answer.