A = {x € R |x<3}
B = {x € R |3 < x < 10}
A U B=
A-B =
B-A =

A= x€{0,1,2}
B= x{4,5,6,7,8,9}
AUB=0,1,2,4,5,6,7,8,9
A-B=0,1,2
B-A=4,5,6,7,8,9