化简求值：﹣3﹙a³-a²+2a-1﹚-2﹙﹣3a³+2a²-1/2a+2﹚-3(﹣a³-a²+2a+1﹚

分类: 作业答案 • 2021-12-01 09:59:31

问题描述：

化简求值：﹣3﹙a³-a²+2a-1﹚-2﹙﹣3a³+2a²-1/2a+2﹚-3(﹣a³-a²+2a+1﹚
,其中a=﹣2

答

﹣3﹙a³-a²+2a-1﹚-2﹙﹣3a³+2a²-1/2a+2﹚-3(﹣a³-a²+2a+1﹚=-3a³+3a²-6a+3+6a³-4a²+a-4+3a³+3a²-6a-3=6a³+2a²-11a-4=6×(-2)³+2×(-2...