6x^3-13x^2-14x-3
=6x^3-18x^2+5x^2-15x+x-3
=6x^2(x-3)+5x(x-3)+(x-3)
=(x-3)(6x^2+5x+1)
=(x-3)(3x+1)(2x+1)
采用配方法.哦，拆项添项法，对的，谢谢哈！