To simplify this, you would have to turn b^-2 into a positive exponent.
To do this, we have to flip b^-2, which would get rid of the negate from the exponent: -2
3a^4 b^-2 c^3 / b^-2
Then we get the answer:
3a^4 c^3
------------
b^-2
I have a picture to clarify!
I hope this helped, let me know if you don't understand! ^.^
