If A and B two are 3x3 matrices, then which one of following is not true:
(A+B)′=A′+B′
(AB)′=A′B′
det(AB)=det(A)det(B)
A(adjA)=|A|I3
If A and B are two 3x3 matrices, then
(AB)′=B′A′ [Reversal Law]
and not (AB)′=A′B′.