Question

D={k|kapartine N si 30 este divizibil(k-2)

Answer 1

multimea divizorilor lui 30={1,2,3,5,6,10,15,30}
⇒ k-2∈{1,2,3,5,6,10,15,30}
⇒ k∈{1-2,2-2,3-2,5-2,6-2,10-2,15-2,30-2}
⇔ k∈{0,1,3,4,8,13,28}
⇒ D={0,1,3,4,8,13,28}