|3x-1|-x=2 ( 1)
Nếu 3x-1 $\geq$ 0
<=> x $\geq$ $\frac{1}{3}$
(1) <=> 3x-1-x=2
<=> 2x - 1 = 2
<=> 2x = 3
<=> x = $\frac{3}{2}$ ( TM )
Nếu 3x-1 < 0
<=> x < 0
(1) <=> -3x-1 - x = 0
<=> -4x - 1 = 0
<=> -4x = 1
<=> x = $\frac{-1}{4}$ ( TM )
Vậy S = { $\frac{3}{2}$ ; $\frac{-1}{4}$ }
∵∴∵∴∵∴∴