Question

Seja A = {x ∈ ℤ / -1 ≤ x < 4}, B = {x ∈ ℕ / x < 7} , então (A – B) é:
A {-1, 0}
B {-1}
C { }
D {5, 6, 7}
E {0}

Answer 1

A = {x ∈ ℤ / -1 ≤ x < 4} = {-1, 0, 1, 2, 3 }
B = {x ∈ ℕ / x < 7} = {0, 1, 2, 3, 4, 5, 6}

Logo, (A-B) = {-1}

Alternativa B.