# math

posted by
**abby**
.

Tell whether each of the following is true for all sets A, B, or C. If false, give a counterexample.?

a. A-B=A- ∅

b. (A ¾B) ̅=(A ) ̅¾B ̅

c. A ¿(B¾C)=(A¿B)¾C

d. (A-B)¿A=A

e. A-(B¿C)=(A-B)¿(A-C)