题目

．计算（﹣1）1+（﹣1）2+…+（﹣1）2000= ．                                                                                                                                                 答案：0 ．                                                                                                  【考点】有理数的乘方．                                                                          【分析】在200方程（x+2）（2x﹣1）=0的解是： ．