b. 2x + 1/ -3 - 2x^2 + 3/ -4 > x(5-3x)/-6 - 4x + 1/-5
Giải thích
b. 2x+1−3−2x2+3−4>x5−3x−6−4x+1−5
⇔−2x−13+2x2+34>−x5−3x6+4x+15⇔20.−2x−1+15.2x2+360>−10x.5−3x+12.4x+160⇔−40x−20+30x2+4560>−50x+30x2+48x+1260⇔30x2−40x+25>30x2−2x+12⇔−38x>−13⇔x<1338
Vậy S=xx<1338