题目内容:
计算或化简:
①;
②;
③;
④﹣12006﹣(1﹣0.5)×[3﹣(﹣3)2];
⑤3x2y﹣4xy2﹣3+5x2y+2xy2+5;
⑥3(2x2﹣y2)﹣2(3y2﹣2x2);
⑦先化简再求值:﹣2y3+(2x3﹣xyz)﹣2(x3﹣y3+xyz),其中x=1,y=2,z=﹣3.
参考答案:
计算或化简:
①;
②;
③;
④﹣12006﹣(1﹣0.5)×[3﹣(﹣3)2];
⑤3x2y﹣4xy2﹣3+5x2y+2xy2+5;
⑥3(2x2﹣y2)﹣2(3y2﹣2x2);
⑦先化简再求值:﹣2y3+(2x3﹣xyz)﹣2(x3﹣y3+xyz),其中x=1,y=2,z=﹣3.