If AAA and BBB are 2×22 \times 22×2 matrices, which is true?
AB=BAAB = BAAB=BA
A+B=B+AA+B = B+AA+B=B+A
A2=AA^2 = AA2=A
det(A+B)=det(A)+det(B)\det(A+B) = \det(A) + \det(B)det(A+B)=det(A)+det(B)