Đáp án:
4) `(-3)/8 . 6/13 + 7/13 . (-3)/8 + 1 3/8`
`= (-3)/8 . (6/13 + 7/13) + 11/8`
`= (-3)/8 . 1 + 11/8`
`= (-3)/8 + 11/8`
`= 1`
5) `1 4/23 + (5/21-4/23)+16/21-1/2`
`= 27/23 + 5/21 - 4/23 + 16/21 - 1/2`
`= (27/23 - 4/23) + (5/21+16/21)-1/2`
`= 1 + 1 - 1/2`
`= 2 - 1/2`
`= 3/2`
6) `(5/6 - 4/5). 1 1/5 + 3/16 : (-1/2)^3`
`= (5/6 - 4/5) . 6/5 + 3/16 : (-1/8)`
`= 1/30 . 6/5 + 3/16 . (-8)`
`= 1/25 + (-3/2)`
`= -73/50`