Originally Posted by

**iwan1981** I need some help with understanding this question as well:

==================================== *A – B* = {*x*|*x* ∈ *A* ∧ *x *∉ B}

*A* = {*a, b, e, f*}

*B* = {b, d, g, f, a}

Match the following to the correct answers.

A – B = ?

B – A = ?

Answers:

a. {a, b, f}

b. {a, b, e, f}

c. {d, g}

d. {e}

====================================

What I understand here is that x has elements in A and that those elements are not part of B.

No. x is not a set. It represents a element in A-B. So your statement should be corrected as, "A-B includes all the elements in A which are not in B".

So when we do A - B the correct answer is: c. {a, b, f}

This is incorrect as a,b and f are in B.

and B - A would be: c. {d, g}

Is this correct?

Correct

Thanks,