Răspuns:
A = {0, 3, 48}
B = {0, 3}
C = ∅
Explicație:
A = {x | x ∈ N, (x + 2) | 50 şi 3 | x}
(x + 2) | 50 ⇒ (x + 2) ∈ D₅₀
(x + 2) ∈ {1, 2, 5, 10, 25, 50}
⇒ x ∈ {-1, 0, 3, 8, 23, 48} ∩ N
x ∈ {0, 3, 8, 23, 48}
3 | x ⇒ x ∈ M₃
⇒ x ∈ {0, 3, 8, 23, 48} ∩ M₃
x ∈ {0, 3, 48}
⇒ A = {0, 3, 48}
B = {x | x ∈ N, (2x + 3) | 18}
(2x + 3) | 18 ⇒ (2x + 3) ∈ D₁₈
(2x + 3) ∈ {1, 2, 3, 6, 9, 18}
2x ∈ {-2, -1, 0, 3, 6, 15}
x ∈ {-1, -1/2, 0, 3/2, 3, 15/2} ∩ N
x ∈ {0, 3}
B = {0, 3}
C = {x | x ∈ N, 4 < 2x < 10 și (2x + 1) | 17}
(2x + 1) | 17 ⇒ (2x + 1) ∈ D₁₇
(2x + 1) ∈ {1, 17}
2x ∈ {0, 16}
nici 0, nici 16 nu indeplinesc conditia 4 < 2x < 10
⇒ C = ∅
