18ab^5c^3/12b^2c: is answer a negative or a positive?

[ppat]

18a b to the 5th power c to the 3rd power divided by 12b to the 2nd power c

the instructor says the answer is a negative

3ab to the 3rd power c to the 3rd power divided by 2

 

[Loren]

Re: is the answer a NEGATIVE OR POSITIVE

If a or b only is a negative, then the answer is negative.