c. 2x^2 - x - 6 > 0

c)2x2−x−6>0⇔(x−2)(3x+2)>0⇔x−2>03x+2>0x−2<03x+2<0⇔x>2x>−23x<2x<−23⇔x>2x<−23

Vậy x>2x<−23