Tìm n...

- Hướng dẫn giải

a, n+6$⋮$n+2 => (n+2)+4$⋮$n+2

=> 4$⋮$n+2

=> n$\in${0;2}

b, 2n+3$⋮$n$-$2

=> 2.(n$-$2)+7$⋮$n$-$2

=> 7$⋮$n$-$2

=> n$\in${3;9}

c, 3n$-$1$⋮$3$-$2n

=> 2.(3n$-$1)$⋮$3$-$2n

=> 6n$-$2$⋮$3$-$2n

Ta có: 3(3$-$2n)$⋮$3$-$2n => 9$-$6n$⋮$3$-$2n

Do đó: (6n$-$2)+(9$-$6n)$⋮$3$-$2n

=> 7$⋮$3$-$2n => n$\in${1}