x2+6x+13=0x^{2}+6 x+13=0x2+6x+13=0
x2−6x+15=0x^{2}-6 x+15=0x2−6x+15=0
x2−6x+17=0x^{2}-6 x+17=0x2−6x+17=0
x2−6x+13=0x^{2}-6 x+13=0x2−6x+13=0
x2+7x+13=0x^{2}+7 x+13=0x2+7x+13=0