A = [0 3 -6 6 4 -5 3 -7 8 -5 8 9 3 -9 12 -9 6 15] rref(A) A=[36 51 13 33; 52 34 74 45; 0 7 1.1 3] rref(A) A=[2 3; 1 -5] B=[4 3 6; 1 -2 3] A*B