x2
x
=0
21x2
21x2-20x
21x2-19x
21x2-18x
21x2-17x
21x2-16x
21x2-15x
21x2-14x
21x2-13x
21x2-12x
21x2-11x
21x2-10x
21x2-9x
21x2-8x
21x2-7x
21x2-6x
21x2-5x
21x2-4x
21x2-3x
21x2-2x
21x2-x
21x2+x
21x2+2x
21x2+3x
21x2+4x
21x2+5x
21x2+6x
21x2+7x
21x2+8x
21x2+9x
21x2+10x
21x2+11x
21x2+12x
21x2+13x
21x2+14x
21x2+15x
21x2+16x
21x2+17x
21x2+18x
21x2+19x
21x2+20x
21x2+21x
21x2+22x
21x2+23x