x的3次方+3x的2次方-4x-12

问题描述:

x的3次方+3x的2次方-4x-12

x的3次方+3x的2次方-4x-12
=x²(x+3)-4(x+3)
=(x+3)(x²-4)
=(x+3)(x²-2²)
=(x+3)(x+2)(x-2)