To invert a 3 by 3 matrix A, we have to solve three systems of equations: Ax 1 = e 1 and Ax 2 = e 2 = (0,1,0) and Ax 3 = e 3 = (0,0,1). Gauss-Jordan finds A−1 this way. The Gauss-Jordan method computesA−1 by solving all n equations together. Usually the “augmented matrix” [A b] has one extra column b. Now we have three right sides e 1 ...