Respuesta :

[tex]x'=x+xy=x(1+y)=0\implies x=0\text{ or }y=-1[/tex]

[tex]y'=-y-xy=-y(1+x)=0\implies y=0\text{ or }x=-1[/tex]

There are 4 critical points: (0, 0), (0, -1), (-1, 0), and (-1, -1).