giúp mik câu hỏi này vs ạ 1 13/15 . 0,75 – (11/20 +25%) : 3/7

`1 13/15. 0,75 – (11/20 + 25%) : 3/7`

`= 28/15 . 3/4 – ( 11/20 + 1/4) . 7/3`

`= 7/5 – (11/20 + 5/20) . 7/3`

`= 7/5 -4/5 . 7/3`

`= 7/5 – 28/15`

`= 21/15- 28/15`

`=-7/15`