計算:
(1)a-(5a-3b)+(2b-a);
(2)8a+2b+(5a-b);
(3)(5a-3b)-3(a2-2b);
(4)-2x2+4x-1;
(5)9x3-2ab+0.25b2a2+ab;
(6)-[-6x2+3(x3-2x2)].
解:(1)原式=a-5a+3b+2b-a=-5a+5b;
(2)原式=8a+2b+5a-b=13a+b;
(3)原式=5a-3b-3a2+6b=-3a2+5a+3b;
(4)原式=-2x2+4x-1;
(5)原式=9x3-ab+0.25b2a2;
(6)原式=6x2-3x3+6x2=12x2-3x3.
分析:(1)先去括號,然后合并同類項求解;
(2)先去括號,然后合并同類項求解;
(3)先去括號,然后合并同類項求解;
(4)直接求解即可;
(5)直接合并同類項求解;
(6)先去括號,然后合并同類項求解.
點評:本題考查了整式的加減,解答本題的關(guān)鍵是掌握去括號法則和合并同類項法則.