x3+3x2-4.
问题描述:
x3+3x2-4.
答
原式=x3+3x2-3-1
=(x3-1)+3(x2-1)
=(x-1)(x2+x+1)+3(x-1)(x+1)
=(x-1)(x2+x+1+3x+3)
=(x-1)(x+2)2.