Răspunsuri

2014-09-25T20:56:07+03:00
-5 ∈ Z (A)
-4 ∈ N (F)
5,6 ∈ Z (F)
 \frac{4}{7}  ∈ Z (F)
 \frac{-20}{1}  ∉ Z (F)