1. The problem statement, all variables and given/known data I need to use matrix multiplication of matrices A-D to obtain matrix E. I also need to set a equal to some value that would allow me to perform this multiplication. 2. Relevant equations The matrixes I need to multiply: A = [1, 1; 0, 1] B = [1, 0; 1, 1] C = [a, 0; 0, 1] D = [1, 0; 0, a] By multiplying the above matrices in some order, I need to obtain the following matrix: E = [0, 1; 1, 0] 3. The attempt at a solution I have tried setting a = 0, 1, -1, 2, and -2 (since those seemed like the most logical choices) and tried all combinations of multiplication. For the life of me, I can't figure out the order the multiplication should go in and which of the four matrices to multiply together to get matrix E. There has to be a simpler way of approaching the problem, right? I just need some help getting onto the right path.