2x2−7x+5=02 x^{2}-7 x+5=02x2−7x+5=0
2x2+7x+5=02 x^{2}+7 x+5=02x2+7x+5=0
2x2−7x−5=02 x^{2}-7 x-5=02x2−7x−5=0
2x2+7x−5=02 x^{2}+7 x-5=02x2+7x−5=0