`2/x` `-` `y/3` `=` `1/6`
`⇒` `1/6` `+` `y/3` `=` `2x`
`⇒` `1/6` `+` `\frac{2y}{6}` `=` `2x`
`⇒` `\frac{1+2y}{6}` `=` `2x`
`⇒` `x(1+2y)` `=` `12`
`⇒` `x` và `1+2y` `∈` `Ư` `12`
Vì `2y` chẵn nên `1+2y` lẻ
`⇒` `x` `∈` {±1; ±2; ±3; ±4; ±6}
`⇒` `1+2y` `∈` {±1; ±3}
@cedric