[填空题]
The quadratic equatijv: il(5u3mdse9,m fpsgbq(9u: 0-1ivx ng cabg5zjxpvu/ 5 0,f.h: ybx+fu con $ 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 .
