2/ Tính a. 15/12 + 5/13 - ( 3/12 + 8/13 ) b. - (3/5 + 3/4) - ( -3/4 + 2/5 ) c. 5/16 - ( 7/15 - 3/16 ) + 17/30 d. 5/3 - ( 7/12 - 2/3 ) + 1/3 e. ( 12/23 + -15/4 ) + ( 10/23 - 1/4 - 2/27 ) huhuhuuuu, giúp e với ạ. Ai giúp thì em cảm ơn nhiều nhaaaa <33

`a)`

`15/12 + 5/13 - ( 3/12 + 8/13 )`

`=15/12 + 5/13- 3/12 - 8/13`

`=(15/12 - 3/12) + (5/13 - 8/13)`

`=1 - 3/13`

`=13/13 - 3/13`

`=10/13`

`b)`

` - (3/5 + 3/4) - ( -3/4 + 2/5 )`

`=-3/5 - 3/4 + 3/4 - 2/5`

`=(-3/5 - 2/5) + (-3/4 + 3/4)`

`=-1 +0`

`=-1`

`c)`

`5/16 - ( 7/15 - 3/16 ) + 17/30`

`=5/16 - 7/15 + 3/16 + 17/30`

`=(5/16 + 3/16) + (-7/15 + 17/30)`

`=1/2 + (-14/30 + 17/30)`

`=1/2 + 1/10`

`=5/10 + 1/10`

`=3/5`

`d)`

`5/3 - ( 7/12 - 2/3 ) + 1/3`

`=5/3 - 7/12 + 2/3 + 1/3`

`=(5/3 + 2/3 + 1/3) - 7/12`

`=8/3 - 7/12`

`=32/12 - 7/12`

`=25/12`

`e)`

` ( 12/23 + -15/4 ) + ( 10/23 - 1/4 - 2/27 )`

`=12/23 + -15/4 + 10/23 - 1/4 - 2/27`

`=(12/23 + 10/23) + (-15/4 - 1/4) - 2/27`

`=22/23 -4 - 2/27`

`=-70/23 - 2/27`

`=-1936/621`.