a)-1 ϵ Z
b)71237123 ϵ N
c)3.05 ϵ Q
d)−2/3 ϵ Q
e)1035 ϵ N
a) \(-1\in Z\Rightarrow-1\in Q\)
b \(\frac{7}{123}\in Q\)
c) \(3,05\in Q\)
d) \(-\frac{2}{3}\in Q\)
e) \(1035\in N\Rightarrow1035\in Z\Rightarrow1035\in Q\)
N: 1035
Z: -1, 1035
Q: -1; 7/123; 3,05; -2/3; 1035