Need help with this MATLAB. Could you please explain as well and just simple code. Thank you

PROBLEM 3: Let An be the n x n matrix with 8 on the main diagonal and 3 elsewhere. For example, [8 3 31 A3 3 8 3 13 3 8 a) For n 3,4,5 1. Use Matlab pre-programmed matrices (eye, ones, zeros) and matrix operations, to efficiently input An Hint: think of An as a sum of two matrices. 2. Compute An 1 using a Matlab command and display the result with rational entries Hint: help format b) Propose a general form for An expressed in terms on n c) Check your theory for n- 6. PROBLEM 4: Consider the matrix D A4 4,-2,1,5; 3, 8, 2, -1; 6, 8, 9, 2; 2, 3, -1, 01. (with A4 as in problem 30. 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 r) where stands for transposed; (c)det(D (d) det 3 D); (e det (D 1). Hint: If your answers appear as rational fraction, you might want to change your default for format