Question

因式分解x9加x6加x3减3X后的数字是次方

Answer 1

x^9+x^6+x^3-3

=x^9-1+x^6+x^3-2

=(x^3-1)(x^6+x^3+1)+(x^3+2)(x^3-1)

=(x^3-1)[(x^6+x^3+1)+(x^3+2)]

=(x-1)(x^2+x+1)(x^6+2x^3+3)