Răspuns:
Explicație pas cu pas:
A = {4 intregi si 1/6 ; 2,(3) ; -178 ; 8/2 ; -6/(-1) ; 4/17}
4 intregi si 1/6 = (4·6 +1)/6 = 25/6 ∈ Q
2,(3) = (23-2)/9 = 21/9⁽³ = 7/3 ∈ Q
-178 = -178 ∈ Z,Q
8/2 = 4 ∈ Z,Q,N
-6/(-1) = 6 ∈ Z,Q,N
4/17 = 4/17 ∈ Q =>
A = { 25/6 ; 7/3 ; -178 ; 4 ; 6 ; 4/17}
a) A ∩ Z = { -178 ; 4 ; 6} => 3 elemente
b) B = {x ∈ A I x > 0 } => B = {25/6 ; 7/3 ; 4 ; 6}
c) C = {x ∈ A I x ∈ Q - N} => C = {25/6 ; 7/3 ; -178 ; 4/17}
