9x2−12x+5=09 x^{2}-12 x+5=09x2−12x+5=0
5x2−4x+1=05 x^{2}-4 x+1=05x2−4x+1=0
5x2+4x+1=05 x^{2}+4 x+1=05x2+4x+1=0
25x2−20x+3=025 x^{2}-20 x+3=025x2−20x+3=0