Đáp án:
$a/$ `1 1/5 - 8/5x = -3 2/3`
`⇔ 6/5 - 8/5x = (-11)/3`
`⇔ 8/5x = 6/5 - (-11)/3`
`⇔ 8/5x = 73/15`
`⇔ x = 73/15 : 8/5`
`⇔ x = 73/24`
`text{Vậy x=}` `73/24`
$b/$ `|2x - 1| - 6/7 = 1/7`
`⇔ |2x - 1| = 1/7 + 6/7`
`⇔ |2x - 1| = 1`
`⇔ 2x - 1 = 1` `text{hoặc}` `2x - 1= -1`
`⇔ 2x = 2` `text{hoặc}` `2x = 0`
`⇔ x = 1` `text{hoặc}` `x = 0`
`text{Vậy x = 1, x = 0}`