5x2+2x−6=05 x^{2}+2 x-6=05x2+2x−6=0
x2−5x+6=0x^{2}-5 x+6=0x2−5x+6=0
3x2−2x+5=03 x^{2}-2 x+5=03x2−2x+5=0
x2−6x+5=0x^{2}-6 x+5=0x2−6x+5=0