Respuesta :

gmany

Answer:

[tex]\large\boxed{A\subset B}[/tex]

Step-by-step explanation:

[tex]A=\{1,\ 2\},\ B=\{1,\ 2,\ 3,\ 4\}\\\\A\subset B,\ \text{because all elements of the set A are the elements of the set B.}[/tex]