` (7/8 -1/4)^2 : 5/8 +sqrt9/16-(2017/2018-2018/2019)^0 + |1/4 -6/5|`
`=(7/8 -2/8)^2 : 5/8 +sqrt9/16-(2017/2018-2018/2019)^0 + |5/20 -24/20|`
`=(5/8)^2 : 5/8 + 3/16 - 1 + |-19/20|` `(2017/2018-2018/2019)^0=1` vì số nào mũ 0 bằng 1
`=25/64 : 5/8 + 3/16 -1 + 19/20`
`=25/64. 8/5 + 3/16 -16/16 +19/20`
`=5/8 +(-13/16) +19/20`
`=50/80 + (-65/80) + 76/80`
`=(50 +(-65) +76)/80`
`=61/80`