Đáp án:
`↓↓`
Giải thích các bước giải:
`a) 3n+5 vdots n-2`
`=> 3(n-2)+11 vdots n-2`
Mà `3(n-2) vdots n-2`
`=> 11 vdots n-2`
`=> n-2 in Ư(11)`
`=> n-2 in {-11; -1; 1; 11}`
`=> n in {-9; 1; 3; 13}`
`b) 2n+5 vdots n+2`
`=> 2(n+2)+1 vdots n+2`
Mà `2(n+2) vdots n+2`
`=> 1 vdots n+2`
`=> n+2 in Ư(1)`
`=> n+2 in {-1; 1}`
`=> n in {-3; -1}`
`c) 2n-1 vdots n+2`
`=> 2(n+2)-5 vdots n+2`
Mà `2(n+2) vdots n+2`
`=> 5 vdots n+2`
`=> n+2 in Ư(5)`
`=> n+2 in {-5; -1; 1; 5}`
`=> n in {-7; -3; -1; 3}`
`d) 3n+2 vdots 2n-1`
`=> 6n+4 vdots 2n-1`
`=> 3(2n-1)+7 vdots 2n-1`
Mà `3(2n-1) vdots 2n-1`
`=> 7 vdots 2n-1`
`=> 2n-1 in Ư(7)`
`=> 2n-1 in {-7; -1; 1; 7}`
`=> 2n in {-6; 0; 2; 8}`
`=> n in {-3; 0; 1; 4}`
