(x^2+3)(x^2-3)-(2x^3+6x^2)
=(x^2+3)(x^2-3)-2x(x^2+3)
=(x^2+3)(x^2-3-2x)原式打错，应是x＾4-2x＾3－6x＾2+6x+9你给了我思路，答案是（x＾2-3）（x＾2-2x-3）对不