3x2−2x−6=03 x^{2}-2 x-6=03x2−2x−6=0
3x2−2x+6=03 x^{2}-2 x+6=03x2−2x+6=0
2x2−3x−6=02 x^{2}-3 x-6=02x2−3x−6=0
