`a)8÷m=>m∈Ư(8)={1; 2; 4; 8}`
`b)9÷3n=>3n∈Ư(9)={1; 3; 9} =>n={1; 3}`
`c)10÷(2n+1)=>(2n+1)∈Ư(10)={1; 2; 5; 10}`
`=>2n={0; 1; 4; 5}=>n={0; 2}`
`d)15÷(n-3)=>(n-3)∈Ư(15)={1; 3; 5; 15}`
`=>n={4; 6; 8; 18}`
`e)10÷(n+1)=>(n+1)∈Ư(10)={1; 2; 5; 10}`
`=>n={0; 1; 4; 9}`
`f)(n+5)÷(n+1)`
`=>(n+5)-(n+1)÷(n+1)`
`=>n+5-n-1 ÷(n+1)`
`=>4 ÷ (n+1)`
`=>(n+1)∈Ư(4)={1; 2; 4}`
`=>n={0; 1; 3}`
