x的三次方+3x²-4x-12(因式分解) x-1 分之X²-x-1计算
问题描述:
x的三次方+3x²-4x-12(因式分解) x-1 分之X²-x-1计算
答
x³+3x²-4x-12
=x²﹙x+3﹚-4﹙x+3﹚
=﹙x+3﹚﹙x²-4﹚
=﹙x+3﹚﹙x+2﹚﹙x-2﹚
x²/﹙x-1﹚-x-1
=[x²-﹙x+1﹚﹙x-1﹚]/﹙x-1﹚
=1/﹙x-1﹚