﹙2x+3y﹚-﹙2x+y﹚﹙2x-y﹚,其中x＝三分之一,y＝﹣

分类: 作业答案 • 2022-06-03 13:15:20

问题描述：

答

﹙2x+3y﹚-﹙2x+y﹚﹙2x-y﹚,=4x+12xy+9y-(4x-y) =4x+12xy+9y-4x+y =12xy+10y =12×1/3×(-1/2)+10×(-1/2) =-2+2.5 =0.5