*Lời giải :
`a) -5 (x + 1/5) - 1/2 (x - 2/3) = 3/2x - 5/6`
`⇔ -5x -1 - 1/2x + 1/6 = 3/2x - 5/6`
`⇔ (-5x - 1/2x) + (-1 + 1/6) = 3/2x - 5/6`
`⇔ (-11)/2x - 5/6 = 3/2x - 5/6`
`⇔ (-11)/2x - 3/2x = 5/6 - 5/6`
`⇔ -7x = 0`
`⇔ x = 0`
Vậy `x= 0`
`b) 3 (x - 1/2) - 5 (x + 3/5) = -x + 1/5`
`⇔ 3x - 3/2 - 5x - 3 = -x + 1/5`
`⇔ (3x - 5x) + (-3/2 - 3) = -x + 1/5`
`⇔ -2x - 9/2 = -x + 1/5`
`⇔ -2x + x = 9/2 + 1/5`
`⇔ -x = 47/10`
`⇔ x = -47/10`
Vậy `x = -47/10`