human
Factorise a single bracket containing a linear expression by taking out a single numeric common factor (e.g. 6) Factorise fully \( 18 a-12 \) \( 18(a-6) \)
gpt
When factorising into single brackets, factorises the first term correctly but subtracts the number outside the bracket with the second term in the expression to find the second term in the bracket