(x−4)2=....\left(x-4\right)^2=....(x−4)2=....
x2−8x−16x^2−8x−16x2−8x−16
x2+8x+16x^2+8x+16x2+8x+16
x2−8x+16x^2-8x+16x2−8x+16
x2+8x−16x^2+8x−16x2+8x−16