A.
[tex]x \leqslant 16[/tex]
x apartine N*
=> A = {1, 2, 3, ..., 16}
B = x^3 <= 64
[tex] \sqrt[3]{x ^{3} } \leqslant \sqrt[3]{64} \\ x \leqslant 4[/tex]
x apartine N*
=> B = {1, 2, 3, 4}
A int. B = {1, 2, 3, 4}
A reunit B = {1, 2, ..., 16}
A \ B = {5, 6, 7, ..., 16}
B \ A = multimea vida