Question

3n+2 chia hết cho n+2

Answer 1

\(3n+2\text{⋮}\left(n+2\right)\)

\(\left(3n+6\right)-4\text{⋮}\left(n+2\right)\)

\(3\left(n+2\right)-4\text{⋮}\left(n+2\right)\)

Vì \(3\left(n+2\right)\text{⋮}n+2\)

⇒ \(4\text{⋮}n+2\)

⇒ \(n+2\) ∈ Ư(4)=\(\left\{1,2,4\right\}\)

Bạn thay vào nữa là được

Answer 2

=> 3n+6-6-2 chia hết cho n+2

=> 3.(n+2)-8 chia hết cho n+2

=> 8 chia hết cho n+2

=> n+2={8;4;2;1;-1;-2;-4;-8}

=> n={6;2;0;-1;-3;-4;-6;-10}