x2−1=0x^{2}-1=0x2−1=0
x2−8x+1=0x^{2}-8 x+1=0x2−8x+1=0
x2+1=0x^{2}+1=0x2+1=0
x2+8x+1=0x^{2}+8 x+1=0x2+8x+1=0
