TH1: $x < 0$ ($x$ âm)
$| 2x - 4 | - | x - 3 | = - 4x$
$⇔ - 2x - 4 - ( - x - 3) + 4x = 0$
$⇔ - 2x - 4 + x + 3 + 4x = 0$
$⇔ 3x - 1 = 0$
$⇔ x =$ $\frac{1}{3}$
TH2: $x > 0$ ($x$ dương)
$| 2x - 4 | - | x - 3 | = - 4x$
$⇔ 2x - 4 - x + 3 + 4x = 0$
$⇔ 5x - 1 = 0$
$⇔x =$ $\frac{1}{5}$