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