If A and B are invertible matrices of the same order, then

AB = BA $(AB)^{-1}=B^{-1}A^{-1}$ $(AB)^{-1}=A^{-1}B^{-1}$ $AB^{-1}=B^{-1}A$

$(AB)^{-1}=B^{-1}A^{-1}$