Consider the system of linear equations + 12 + 8x3 + 812 + 13 Br1 + 12 + where r1, 12 and r3 are unknown variables, and parameter S is an arbitrary real number. (a) Write down the system in the matrix form, Ax = b. Calculate all cofactors and write down the cofactor matrix C for matrix A. (b) Calculate the determinant of matrix A. (c) For 8 # 1, -2 calculate the inverse matrix A- using the cofactor method and find the solution to the system. Please make sure to simplify the expressions. (d) Is it true that the system has solutions when 8 = 1? (e) Is it true that the system has solutions when 8 = -2