Giải thích các bước giải:
`a)`
`5/7 + 2/3x = 3/10`
`⇔ 2/3x = 3/10 - 5/7 = -29/70`
`⇔ x = -29/70 : 2/3 = -87/140`
`Vậy x = -87/140`
`b)`
`3/4x - 1/2 = 3/7`
`⇔ 3/4x = 3/7 + 1/2 = 13/14`
`⇔ x = 13/14 : 3/4 = 26/21`
`Vậy x = 26/21`
`c)`
`-22/15x + 1/3 = |-2/3 + 1/5|`
`⇔ -22/15x + 1/3 = |-10/15 + 3/15|`
`⇔ -22/15x + 1/3 = 7/15`
`⇔ -22/15x = 7/15 - 1/3 = 2/15`
`⇔ x = 2/15 : (-22/15) = -1/11`
`Vậy x = -1/11`