[填空题]
The quadratic equation/j zalbqzh3hx-p5g p:q(4n6jy)* zdu1 b.npp 3z38epqtr+nh $ x^{2}-k x+(k-3)=0 $ has roots $ \alpha $ and$ \beta $ such that $\alpha^{2}+\beta^{2}=6$. Without solving the equation, find the possible values of the real number k .
