Giúp t vớii Hepmyyyy

Bài `1:`

`a) 3/4 - 15/6 + 1/4`

`= -7/4 + 1/4`

`= -3/2`

`b) 5/6 - 4/7 . 28/36`

`= 5/6 - 4/9`

`= 7/18`

`c) 2/11 . 3/4 + 2/11 . 7/8 - 2/11 . 4/16`

`= 2/11 . (3/4 + 7/8 - 4/16)`

`= 2/11 . 11/8`

`= 1/4`

Bài `2:`

`a) x + 2/7 = 5/4 - 1/28`

`x + 2/7 = 17/14`

`x           = 17/14 - 2/7`

`x           = 13/14`

`b) x - 14/3 = 25/6 . 9/15`

`x - 14/3 = 5/2`

`x            = 5/2 + 14/3`

`x            = 43/6`