Answer:
B. and D.
Step-by-step explanation:
When you multiply exponents, you add them
3 + (-6) = -3
The base always stays the same

is one answer

Do this formula for the question and you get 1/(7^3)
Answer:
uhm i would say the second one but i might be very wrong
Step-by-step explanation:
I don't know what posts are but i'm assuming you would subtract 21 from 17 and get 4.