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