Question

اذا كانت      A equals open curly brackets space 1 space comma space space 2 space comma space 3 space space close curly brackets space space space comma space space B equals open curly brackets space 3 space comma space 4 space close curly brackets   فان  B minus A equals
empty set
open curly brackets space 1 space comma space space 2 space comma space 3 space space close curly brackets
open curly brackets space 3 space comma space 4 space close curly brackets
open curly brackets space 4 space close curly brackets

Answer 1

{4}