Determine the values of the parameter s for which the system has a unique solution, and describe the solution.

\f\fAn Inverse Formula Let A be an invertible n x n matrix. Then A-I adj A det A17. Show that if A is 2 x 2, then Theorem 8 gives the same formula for A"1 as that given by Theorem 4 in Section 2.2. \f\f