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