`15/29 = 1 - 14/29`
`37/51 = 1 - 14/51`
Do `14/29 > 14/51`
`=> 1 - 14/29 < 1 - 14/51`
`=> 15/29 < 37/51`
Vậy ...
--------------------------------
`8/15 < 10/15 = 2/3`
`172/179 > 172/180 > 120/180 = 2/3`
`=> 8/15 < 172/179`
`=> -8/15 > - 172/179`
Vậy ...
`15/37 = 1 - 22/37`
`19/36 = 1 - 17/36`
Mà `22/37 > 22/44 = 1/2 = 18/36 > 17/36`
`=> 1 - 22/37 < 1 - 17/36`
`=> 15/37 < 19/36 `
Vậy ...
-------------------------------------
`27/151 < 27/135 = 1/5 = 29/145 < 29/139`
`=> -27/151 > -29/139`
Vậy ...