The difference set [tex]A\setminus B[/tex] is the set of all elements that belongs to A, but not to B. These elements are
[tex]A\setminus B = \{2,\ 6,\ 9\}[/tex]
The complementary set is to be considered with respect to the universe set U, so we have to consider all the elements of the universe that are not in our set:
[tex](A\setminus B)' = \{1,\ 3,\ 4,\ 5,\ 7,\ 8,\ 10\}[/tex]
