`2)x+9 vdots x+4`
Vì `x+4 vdots x+4`
`=>{(x+9)-(x+4)}/(x+4)`
`=>5/(x+4)`
`=>5 vdots x+4`
`=>x+4 in Ư(5)={+-1;+-5}` ( làm như tìm x khi x=-1; x=1;...)
`=>x in {-3; -5; 1; -9}`
`2)x+10 vdots x-3`
`=>x+13-3 vdots x-3`
Vì `x+3 vdots x-3`
`=>{(x+13-3)-(x-3)}/(x-3)`
`=>13/(x-3)`
`=>13 vdots x-3`
`=>x-3 in Ư(13)={+-1; +-13}` (làm như tìm x khi x-3=1; x-3=-1;...)
`=>x in {4; 2; 16; -10}`