`= x(y+2) + y+2 = 3`.
`=> (x+1)(y+2) = 3`
`=> x + 1 in Ư(3)`
`=> x + 1 = 1 => x = 0`
`y + 2 = 3 => y = 1`.
`=> x +1 = -1 => x = -2`
`y + 2 = -3 => y = -5`
`=> x + 1 = 3 => x = 2`
`y + 2 = 1 => y = -1`
`=> x + 1 = -3 => x = -4`
`y + 2 = -1 => y = -3`.