please help with solutions

1. Determine the matrices C = 2A + B and D = A - 38 if 2 A B 2. Determine the products C = AB and D = BA if -5 A = -1-73 - A 7 3. Determine the inverse of the matrix A. 3 A = 3 8 4. Solve the following systems of simultaneous equations by any direct method a) 4x1 - 2x2 + 3x3 = 37.2 3x1 + 5x2 - X3 =-7.2 X1 - 4x2 + 2x3 = 30.3 b) 6x1 + 15x2 - 24x3 + 40x4 = 190.9 15x1 + 9X2 - 13x3 69.8 -24x1 - 13x2 + 8x3 - 11X4 = -96.3 40X - 11x3 + 5x4 = 119.35