-(2a²+5)-(3a²-2)-2(-4a²-1)这道题答案是3a²-12(2b-3a)-3(2a-3b)这道题答案是13b-12a14(abc-2a)+3(6a-2abc)这道题答案是8abc-10a5ab-{2a²b-[3ab-(4ab²-a²b)]}2a²-{-3a-[4a²-(3a²-a)+(a-a²)]}4a²-[a²+(4a²-2a)-2(a²-3a]要步骤,谢谢了,我只是懒的做,我会做的