Answer:
4x is the greatest common factor of those two.
Explanation:
(-16x + 12x)
4x (-4 + 3)
4x is the GCF
Why you may ask is 4x the GCF because when you divide 4x from both you're left with -4 + 3...... you can't take out the negative from the 16 because when you check your work negative 4x times 3 gives you negative 12x which isn't the equation you started with. So positive 4x times 3 give you 12x.
Hopes this helps!!!