-(5/12) is equivalent to (5/-12).
The fraction -(5/12) can be described as the opposite of a positive number divided by a positive number. a positive number divided by a positive number results in a Positive Quotient and its opposite is always Negative.
The fraction 5/-12 can be described as a positive number divided by a negative number, which always results in a Negative quotient.
The fraction have the same value, so Liam is correct.