Andalucía 2016-P5

Discutir y resolver el siguiente sistema lineal: \[\left \{ \; \begin{array}{c} -x &+& (1+\lambda) y &+& (2-\lambda)z &+& \lambda t &=& 3 \\ \lambda x &+& y &+& (2-\lambda)z &+& \lambda t &=& 2 \\ \lambda x &+& \lambda y &+& (2-\lambda)z &+& \lambda t &=& 2 \\ \lambda x &+& \lambda y &+& (2-\lambda)z &-& t &=& 2 \end{array} \right.\]