Đáp án:
`a) 7/6 - 1/6 : 2/3`
`= 7/6 - 1/4`
`= 11/12`
`b) 23 1/4 : 7/5 - 13 1/4 . 7/5`
`= 93/4 . 5/7 - 53/4 . 7/5`
`= 465/28 - 371/20`
`=-68/35`
`c) 3^{27}/(9^5 . 3^{16})`
`= 3^{27}/( (3^2)^5 . 3^{16})`
`= 3^{27}/(3^{10} . 3^{16})`
`= 3^{27}/3^{26}`
`= 3`
`d) -5/7 . [3,5 - (3/2 + -5/4)^2 : 5/2] . 4/3`
`= -5/7 - [3,5 - (1/4)^2 . 2/5] . 4/3`
`= -5/7 - [3,5 - 1/16 . 2/5] . 4/3`
`= -5/7 - [3,5 - 1/40] . 4/3`
`= -5/7 - 139/40 . 4/3`
`= -5/7 - 139/30`
`= -1123/210`
