$a$) `5/6 + x = 1/2`
`⇔ x = 1/2 - 5/6`
`⇔ x = -2/6`
`⇔ x = -1/3`
Vậy `x=-1/3`
$b$) `x - 1/3 = -5/8`
`⇔ x = -5/8 + 1/3`
`⇔ x = -7/24`
Vậy `x=-7/24`
$c$) `2/3 . (x-1/2) = 1/4`
`⇔ x - 1/2 = 1/4 : 2/3`
`⇔ x - 1/2 = 3/8`
`⇔ x = 3/8 + 1/2`
`⇔ x = 7/8`
Vậy `x = 7/8`
$d$) `2/15 . (x + 1/6) = 1/3`
`⇔ x + 1/6 = 1/3 : 2/15`
`⇔ x + 1/6 = 5/2`
`⇔ x = 5/2 - 1/6`
`⇔ x = 14/6`
`⇔ x = 7/3`
Vậy `x=7/3`
$e$) `(5/7 x - 1) : 1/7 = 1/2`
`⇔ 5/7 x - 1 = 1/2 . 1/7`
`⇔ 5/7 x - 1 = 1/14`
`⇔ 5/7 x = 15/14`
`⇔ x = 15/14 : 5/7`
`⇔ x = 3/2`
Vậy `x=3/2`
$f$) `(2/3 x + 5) : 2 = 4/9`
`⇔ 2/3 x + 5 = 4/9 . 2`
`⇔ 2/3 x + 5 = 8/9`
`⇔ 2/3 x = 8/9 - 5`
`⇔ 2/3 x = -37/9`
`⇔ x = -37/6`
Vậy `x=-37/6`
$g$) `2 9/16 x + 5 = 1/20 : {-2}/5`
`⇔ 41/16 x + 5 = -1/8`
`⇔ 41/16 x = -1/8 - 5`
`⇔ 41/16 x = -41/8`
`⇔ x = -2`
Vậy `x=-2`
$h$) `(3 1/7 x - 2) : 4 = -1/3`
`⇔ 22/7 x - 2 = -1/3 . 4`
`⇔ 22/7 x- 2 = -4/3`
`⇔ 22/7 x = 2/3`
`⇔ x = 7/33`
Vậy `x=7/33`
