Question

tìm n:

(n + 6) ⋮(2n - 1)

Answer 1

Bạn trên sai rồi -.-

Giải

\(n+6⋮2n-1\)

\(\Rightarrow2\left(n+6\right)⋮2n-1\)

\(\Rightarrow2n+12⋮2n-1\)

\(\Rightarrow2n-1+13⋮2n-1\)

\(\Rightarrow2n-1\inƯ_{13}\)

\(\Rightarrow2n-1\in\left\{-1,1,-13,13\right\}\)

\(\Rightarrow n\in\left\{0,1,-6,7\right\}\)

Answer 2

( n + 6 ) ⋮ ( 2n - 1 )

⇒ 2 ( n + 6 ) ⋮ ( 2n - 1 )

2n + 12 ⋮ 2n - 1

⇒ 2n - 1 + 13 ⋮ 2n - 1

2n - 1 ⋮ 2n - 1

⇒ 1 ⋮ 2n - 1

⇒ 2n - 1 ϵ Ư (1)

⇒ 2n - 1 = 1

⇒ 2n = 2

⇒ n = 1