bài1 A. 3/4 - 15/6 + 1/4 , B. 5/6 - 4/7 . 28/36 , C. 2/11 . 3/4 + 2/11 . 7/8 - 2/11 . 4/16 bài2 A. x + 2/7 = 5/4 - 1/28 , B. x - 14/3 = 25/6 . 9/15

Bài `1:`

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

`=1-15/6`

`=-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`

Vậy `x=13/14`

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

`⇒x-14/3=5/2`

`⇒x=5/2+14/3`

`⇒x=43/6`

Vậy `x=43/6`