1. The problem statement, all variables and given/known data If A is a 2x2 matrix, then det (2A * adj(A)^-1) = ? 2. Relevant equations Adj(A)A = det(A)I 3. The attempt at a solution First, I separated them so it became det(2A) * det (1/ adj(A)) Then taking the 2 out, and it becomes 2^2, so 4 det(A) * det(1/ adj(A)) adj(A) = det(A) * A^-1, rearranged from the equation above. So: 4 det(A) * det (A/det(A)), and I get stuck at around here, because I end with 4 det(A) ^2 * det (1/det(A)), however I don't know what the determinant of the determinant of A is. Could someone clarify this for me? thank you in advance.