X3 +5X -6
问题描述：
X3 +5X -6
答
(x^3-1)+5x-6+1
=(x^3-1)+5x-5
=(x^3-1)+5(x-1)
=(x-1)(x^2+x+1)+5(x-1)
=(x-1)(x^2+x+6)