e. (2x+1)(3x-2) nhỏ hơn bằng 0
Giải thích
2x+1.3x−2≤0
TH1: 2x+1≥03x−2≤0⇔2x≥−13x≤2⇔x≥−12x≤23⇔−12≤x≤23
TH2: 2x+1<03x−2>0⇔2x<−13x>2⇔x<−12x>23⇔x∈∅
Vậy: S=x−12≤x≤23
2x+1.3x−2≤0
TH1: 2x+1≥03x−2≤0⇔2x≥−13x≤2⇔x≥−12x≤23⇔−12≤x≤23
TH2: 2x+1<03x−2>0⇔2x<−13x>2⇔x<−12x>23⇔x∈∅
Vậy: S=x−12≤x≤23