原式=X^3+X^+3X^+3X-9+X^=X^(X+1)+3x(x+1)+(x+3)(x-3)=x(x+1)(x+3)+(x+3)(x-3)=(x+3)(X^+x+x-3)=(x+3)(x^+2x-3)=(x+3)(x+3)(x-1)=(x+3)^(x-1)x的四次方+2x的三次方-9x的平方-2x+8 分解因式原式=X^4-X^-8X^+8+2x^3-2x=x^2(x^-1)-8(x^-1)+2x(x^-1)=(x^-1)(x^+2x-8)=(x^-1)(x+4)(x-2)=(x+1)(x-1)(x+4)(x-2)若3x的三次方-kx的平方+4被3x-1除后余3，则k的值为（ ）a，2b4c9d10