Răspuns:
a) x | 5 ⇔ x ∈ {1, 5}
b) x | 12 ⇔ x ∈ {1, 2, 3, 4, 6, 12}
c) (x + 1) | 7 ⇔ (x + 1) ∈ {1, 7} ⇒ x ∈ {0, 6}
d) (x - 3) | 6 ⇔ (x - 3) ∈ {1, 2, 3, 6} ⇒ x ∈ {4, 5, 6, 9}
e) (2x - 3) | 15 ⇔ (2x - 3) ∈ {1, 3, 5, 15}
⇔ 2x ∈ {4, 6, 8, 18}
⇒ x ∈ {2, 3, 4, 9}
f) (3x - 1) | 21 ⇔ (3x - 1) ∈ {1, 3, 7, 21}
⇔ 3x ∈ {2, 4, 8, 22}
⇔ x ∈ {2/3, 4/3, 8/3, 22/3}
deoarece avem conditia ca x ∈ N ⇒ ecuatia nu are solutii
x ∈ ∅
Explicație pas cu pas:
