Question

Determinati x apartine Z pt care fractia 12$\frac{12}{3x+5}$ apartine N

Answer 1

3x+5 ∈ Divizorilor 12 = {1, 2, 3, 4, 6, 12}

3x+5 ∈ {1, 2, 3, 4, 6, 12} | -5

3x ∈ {-4, -3, -2, -1, 1, 7} | :3

x ∈ {-4/3, -1, -2/3, -1/3, 1/3, 7/3}, dar x ∈ Z => x ∈ {-1}