System of equations giving empty solution

How do I extract the values a, b, c, d after solving the system of equations using the following code? please note rxx(x, k) is a finite value using the command ap.a gives me Empty-sym: 0-by-1 but there exists non-zero solution to this problem. Can anyone help me please?

A = [rxx(x, 0) rxx(x, 1) rxx(x, 2) rxx(x, 3) rxx(x, 4);...
    rxx(x, 1) rxx(x, 0) rxx(x, 1) rxx(x, 2) rxx(x, 3);...
    rxx(x, 2) rxx(x, 1) rxx(x, 0) rxx(x, 1) rxx(x, 2);...
    rxx(x, 3) rxx(x, 2) rxx(x, 1) rxx(x, 0) rxx(x, 1);...
    rxx(x, 4) rxx(x, 3) rxx(x, 2) rxx(x, 1) rxx(x, 0);
    ];

B = zeros(1, 4);
B = [1 B]';

syms a b c d;
X = [1; a; b; c; d];

ap = solve(A*X==B);

[Bruno Luong]

but there exists non-zero solution to this problem

Sorry but I trust more in MATLAB than you.

Answer 1

[Ashutosh Prasad]

To solve a system of linear equation using the function 'solve', you need to input each of the equations in the symbolic representation as an argument to ‘solve’. Alternatively, you can use the ‘linsolve’ function or ‘\’ operator to solve the system of linear equations in matrix form.

Follow this link to learn more: https://www.mathworks.com/help/symbolic/solve-a-system-of-linear-equations.html