Zeige, dass das Polynom X3+2X2−5{\displaystyle {}X^{3}+2X^{2}-5} in Q[X]{\displaystyle {}\mathbb {Q} [X]} irreduzibel
![{\displaystyle {}\mathbb {Q} [X]}](https://wikimedia.org/api/rest_v1/media/math/render/svg/05854fb7f5090d865105d7297fa178c8eb802fbf)