0 4. (14 points) Let A = W N N 1 (a) Find the inverse matrix of A(i.e.A") using row operations. X1 + 2x3 = -3 (b) Use part (a) to solve for the system _ 2x1 - X2+3x3 = 4 4x1 + X2 + 8X3 = 6 5. (8 points) Determine whether each statement is true or false. (a) The columns of an invertible nxn matrix A always spans R" (b) If P and A are nxn invertible matrices then det(P-1AP) = detA (c) If A is an nxn matrix, then the equation Ax = b has at least one solution for each b in ". (d) If A and B are 3x3 and B = [b1 b2 b3], then AB = [Ab, + Ab2 + Ab3]. (e) det(A + B) = detA + detB