Tính bằng cách thuận tiện c) 7/9 - 1/3 - 1/6 - ( 1/8 + 1/24) = d) ( 5/8 + 5/9) - 3/8 - 2/9 =

`c) 7/9-1/3-1/6-(1/8+1/24)`

`=7/9-3/9-1/6-(3/24+1/24)`

`=4/9-1/6-4/24`

`=4/9-1/6-1/6`

`=4/9-(1/6+1/6)`

`=4/9-2/6`

`=4/9-1/3`

`=4/9-3/9`

`=1/9`

``

`b)(5/8+5/9)-3/8-2/9`

`=5/8+5/9-3/8-2/9`

`=(5/8-3/8)+(5/9-2/9)`

`=2/8+3/9`

`=1/4+1/3`

`=3/12+4/12`

`=7/12`