合并同类项 ⊙ 2x-[2﹙x+3y﹚-3﹙x-2y﹚] ⊙ 2x-3y-1-2x+y ⊙ 5﹙2x-7y﹚-3﹙4x-10y﹚

问题描述:

合并同类项 ⊙ 2x-[2﹙x+3y﹚-3﹙x-2y﹚] ⊙ 2x-3y-1-2x+y ⊙ 5﹙2x-7y﹚-3﹙4x-10y﹚
⊙3﹙3a²-2ab﹚-2﹙4a²-ab﹚

⊙ 2x-[2﹙x+3y﹚-3﹙x-2y﹚] =2x-(2x+6y-3x+6y)=2x-(12y-x)=2x+x-12y=3x-12y⊙ 2x-3y-1-2x+y=-2y-1⊙ 5﹙2x-7y﹚-3﹙4x-10y﹚=10x-35y-12x+30y=-2x-5y⊙3﹙3a²-2ab﹚-2﹙4a²-ab﹚=9a²...