x2−px−q=0x^{2}-p x-q=0x2−px−q=0
x2−px+q=0x^{2}-p x+q=0x2−px+q=0
px2−x+q=0p x^{2}-x+q=0px2−x+q=0
x2+px+q=0x^{2}+p x+q=0x2+px+q=0
