Help me with this MATLAB code:

(a) Please make a MATLAB code for LU decomposition of an arbitrary matrix. Do not use inv( ) function or \. The code must display L, U and L*U matrices. The code must accept a matrix as an input. The code must generate the following error message if the input is not a square matrix: The input matrix must be square.

(b) Please solve the problem through the following procedures:

10x(1)+2x(2)-x(3)=27

-3x(1)-6x(2)+2x(3)=-61.5

x(1)+x(2)+5x(3)=-21.5

Use the code made in (a) to obtain L and U matrices from the system matrix you establish.