Question

sendo a =3,4,5,6,7 b=5,6,7,8,9 determine 
a-b 
b-a
[aUb]-[A INTERCESSAO B]=

Answer 1

A = {3,4,5,6,7}
B = {5,6,7,8,9}
A-B = {3,4}
B-A = {8,9}
[AUB] - [AinterB] = {3,4,5,6,7,8,9} - {5,6,7} = {3,4,8,9}