Question

已知X^2=X+2,化简(X^2+3X+2)•(x^3+x^2-2x-8)

Answer 1

(X^2+3X+2)•(x^3+x^2-2x-8)

=(x^2-x-2+4x+4)(x(x^2-x-2)+2x^2-8)

=(4x+4)(2x^2-8)

=8(x+1)(x^2-4)

=8(x^3-4x+x^2-4)

=8(x(x^2-x-2)+2x^2-2x-4)

=8(2(x^2-x-2))

=0