x2−6x+25=0x^{2}-6 x+25=0x2−6x+25=0
x2+6x+25=0x^{2}+6 x+25=0x2+6x+25=0
x2−6x−25=0x^{2}-6 x-25=0x2−6x−25=0
x2+6x−25=0x^{2}+6 x-25=0x2+6x−25=0