Need Help with MATLAB

Let A_n be the n x n matrix with 8 on the main diagonal and 3 elsewhere. For example, A_3 = [8 3 3 3 8 3 3 3 8] a) For n = 3, 4, 5 Use Matlab pre-programmed matrices (eye, ones, zeros) and matrix operations, to efficiently input A_n. Compute A_n^-1 using a Matlab command and display the result with rational entries. b) Propose a general form for A_n^-1, expressed in terms on n. c) Check your theory for n = 6. Consider the matrix D = A_4 +[4, -2, 1, 5, 3, 8, 2, -1; 6, 8, 9, 2; 2, 3, -1, 0]. (with A_4 as in problem 3). Compute the following five determinants and comment what general properties of determinants your computations at points b-e illustrate: a) det(D); (b) det(D^T) where T stands for transposed; (c)det(D^2); (d) det(3 D); (e) det (D^-1)