$a)$ `16/5- x = 4/5 - 3/10`
`⇔ x = 16/5 - (4/5 - 3/10)`
`⇔ x = 32/10 - 8/10 + 3/10`
`⇔ x = 27/10`
Vậy `x=27/10`
$b$) `1/20 - ( x - 8/5) = 1/10`
`⇔ x - 8/5 = 1/20 - 1/10`
`⇔ x - 8/5 = -1/20`
`⇔ x = -1/20 + 32/10`
`⇔ x = 31/20`
Vậy `x=31/20`
$c$) `1/3 - x = 5/6 - 1/4`
`⇔ x = 1/3 - (5/6 - 1/4)`
`⇔ x = 4/12 - 10/12 + 3/12`
`⇔ x = -3/12`
`⇔ x = -1/4`
Vậy `x=-1/4`
$d$) ` 1/10 - ( x- 3/25) = 1/10`
`⇔ x-3/25 = 1/10 - 1/10`
`⇔ x - 3/25 = 0`
`⇔ x = 0 + 3/25`
`⇔ x = 3/25`
Vậy `x=3/25`.