Question

3n+2chia hết cho 3n+1.tìm n

Answer 1

n=1

Answer 2

3n+2 ⋮ 3n+1

3n+1-1+2 ⋮ 3n+1

3n+1+1 ⋮ 3n+1

Vì 3n+1 ⋮ 3n+1 nên 1⋮ 3n+1

⇒3n+1 ∈ Ư₍₁₎

⇒ 3n+1 ∈ ξ 1 ξ

⇒ 3n ∈ ξ 0 ξ

⇒ n ∈ ξ 0ξ

Vậy n=0

Answer 3

\(3n+2⋮3n+1.\)

\(\Rightarrow\left(3n+1\right)+1⋮3n+1.\)

mà \(3n+1⋮3n+1\Rightarrow1⋮3n+1\in U_{\left(1\right)}=\left\{\pm1\right\}.\)

\(\Rightarrow n\in\left\{0;-\dfrac{2}{3}\right\}.\)

Vậy..........