A=[2, 4, 6; 3, -2, 1; 4, 2, -1];
b=[14; -3; 4];
n=3;


//Complete Forward substitution
A_aug = [A b];
for k=1:n-1
    for i=k+1:n
        for j = k+1:n+1
            A_aug(i,j) = A_aug(i,j) - A_aug(k,j)*A_aug(i,k)/A_aug(k,k);
        end
        for j = 1:k
            A_aug(i,j) = 0
        end
    end

end