function x = gauss(A,b)
[n,m] = size(A);
x = [];
    for k = 1:n
        for i = k+1:n
            m = A(i,k) / A(k,k);
            for j = k:n
                A(i,j) = A(i,j) - A(k,j) * m;
            end

            b(i) = b(i) - b(k) * m;
        end
    end

    for i = n:-1:1
        s = 0;
        for k = i+1:n
            s = s + A(i,k) * x(k);
        end

        x(i) = (b(i) - s) / A(i,i);
    end
end

% TEST:
% A = [1 3 2; 4 5 6; 8 7 6]
% b = [4; 1; 3]
% x = gauss(A, b)