計算(x-4)的四次方=

計算(x-4)的四次方=

(x-4)^4
=[(x-4)^2]^2
=(x^2-8x+16)(x^2-8x+16)
=x^4-8x^3+16x^2-8x^3+64x^2-128x+16x^2-128x+256
=x^4-16x^3+96x^2-256x+256