function x = Gauss_Elimination(A,b)

n = length(b);
x = zeros(n,1);

% Forward Elimination
for i = 1:n-1 

    for j = i+1:n

        mul = A(j,i)/A(i,i); % Multiplier

        for k = i+1:n

            A(j,k) = A(j,k) - mul*A(i,k);

        end

        b(j) = b(j) - mul*b(i);

    end

end

x(n) = b(n)/A(n,n); % Obtain solution for the last variable

% Back Substitution
for i = n-1:-1:1

    sum = b(i);

    for j = i+1:n

        sum = sum - A(i,j)*x(j);

    end

    x(i) = sum/A(i,i);

end

Cuando A = [0 1 1 1; 3 0 3 -4; 1 1 1 2; 2 3 1 3]; b = [0; 7; 6; 6]; x = [4; -3; 1; 2]

Sin embargo, x = [NAN; NAN; NAN; NAN] cuando utilizo esta función.

¿Alguien me dice la razón?