Tính: a) 10,(3)+0,(4) - 8.(6) b) [12,(1) - 2,3(6)] : 4,(21)

`a)` `10,(3)` `+` `0,(4)` `-` `8,(6)`

`=` `10` `3/9` `+` `4/9` `-` `8` `6/9`

`=` `31/3` `+` `4/9` `-` `26/3` 

`=` `85/9` 

`b)` `[12,(1)-2,3(6)]` `:` `4,(21)` 

`=` `877/90` `:` `139/33` 

`=` `877/90` `xx` `33/139` 

`=` `9647/4170`

`#hl`