2x2−2x+1=02 x^{2}-2 x+1=02x2−2x+1=0
2x2+x−12 x^{2}+x-12x2+x−1
2x2+2x−1=02 x^{2}+2 x-1=02x2+2x−1=0
2x2+2x+1=02 x^{2}+2 x+1=02x2+2x+1=0