Question

Tìm n thuộc Z biết:(6n+11)chia hết cho(3n+2)

Answer 1

\(6n+11⋮3n+2\)

\(2\left(3n+2\right)+7⋮3n+2\)

\(\Rightarrow7⋮3n+2\)

\(\Rightarrow3n+2\inƯ\left(7\right)\)

                     _" Tự làm nốt - Hoq chắc :)

Answer 2

\(6n+11⋮3n+2\)

\(\Rightarrow2\left(3n+2\right)+7⋮3n+2\)

\(\Rightarrow7⋮3n+2\)

\(\Rightarrow3n+2\in\left\{7;1;-7;-1\right\}\)

\(\Rightarrow3n\in\left\{5;-1;-9;-3\right\}\)

\(\Rightarrow n\in\left\{-3;-1\right\}\) vì \(n\in Z\)

Answer 3

ta có : \(6n+11⋮3n+2\)

  \(\Rightarrow2\left(3n+2\right)+7⋮3n+2\)

do : \(2\left(3n+2\right)⋮3n+2\Rightarrow7⋮3n+2\Rightarrow3n+2\inƯ\left(7\right)=\left\{1;-1;7;-7\right\}\)

ta có bảng sau :

3n+2	1	-1	7	-7
3n	-1	-3	5	-9
n	-1/3	-1	5/3	-3

 Vậy n = { -1 ; -3 } thì 6n + 11 chia hết cho 3n + 2