x2−x+4=0x^{2}-x+4=0x2−x+4=0
x2−4x+1=0x^{2}-4 x+1=0x2−4x+1=0
x2−23x−1=0x^{2}-2 \sqrt{3} x-1=0x2−23x−1=0
x2+x+23=0x^{2}+x+2 \sqrt{3}=0x2+x+23=0