Đáp án:
$| 4 − 3 x | ≤ 8$
Ta có:
$\left \{ {{4-3x ≤ 8} \atop {4-3x≥-8}} \right.$
$⇔$ $\left \{ {{4-3x-8≤0} \atop {4-3x+8≥0}} \right.$
$⇔$ $\left \{ {{-4-3x≤0} \atop {12-3x≥0}} \right.$
$⇔$ $\left \{ {{-3x≤4} \atop {-3x≥-12}} \right.$
$⇔$ $\left \{ {{x≥-4/3} \atop {x≤4}} \right.$
$⇒ -4/3≤x≤4$
Vậy $S=$[$-4/3;4$]
BẠN THAM KHẢO NHA!!!