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