Question

How to simplify this

Answer 1

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! ^.^