Răspuns:
4. A : x <= 16
x € N*
A = {1, 2, 3, ..., 16}
B : x^3 <= 64
x^3 <= 4^3
x <= 4
x € N*
B = {1, 2, 3, 4}
A u B = A = {1, 2, ..., 16}
A n B = B = {1, 2, 3, 4}
A / B = {5, 6, 7, ..., 16}
B / A = O (multimea vida)
5. a) A = {a}
B = {b, c}
b) A = B = C = {a, b, c}
c) A = C = {a, b, c}
B = O (multimea vida)
