bài 1 a) 1/2 . ( 4/3+ 2/5) - 3/4 (8/9+16/3) b)1/5:1/10 - 1/3 ( 6/5 - 9/4) c) 1/7:5/14 - 3/2 . (1/6 - 7/12) d)-5/4:(1/4- 7/8) + 3/2 . (1/3 - 5/6) e)-7/8 : 21/16 - 5/3 . (1/5 - 7/10)

Bài `1.`

`a)`

`1/2 . ( 4/3 + 2/5 ) - 3/4 . ( 8/9 + 16/3 )`

`= 1/2 . 26/15 - 3/4 . 56/9`

`= 13/15 - 14/3`

`= -19/5`

`b)`

`1/5 : 1/10 - 1/3 . ( 6/5 - 9/4 )`

`= 2 - 1/3 . (-21)/20`

`= 2 - (-7)/20`

`= 47/20`

`c)`

`1/7 : 5/14 - 3/2 . ( 1/6 - 7/12 )`

`= 2/5 - 3/2 . ( -5)/12`

`= 2/5 - (-5)/8`

`= 41/40`

`d)`

`-5/4 : ( 1/4 - 7/8 ) + 3/2 . ( 1/3 - 5/6 )`

`= - 5/4 : (-5)/8 + 3/2 . (-1)/2`

`= 2 - 3/4`

`= 5/4`

`e)`

`-7/8 : 21/16 - 5/3 . ( 1/5 - 7/10 )`

`= -2/3 - 5/3 . (-1)/2`

`= -2/3 + 5/6`

`= 1/6`