(x-v3)^2-2(x-3)(x+3)+(x+v3)^2

(x-v3)^2-2(x-3)(x+3)+(x+v3)^2 = x2-2xv3+v6-2(x2+3x-3x-9)+x2+2xv3+v6= x2-2xv3+v6-2x2+18+x2+2xv3+v6= 2v6+18