不等式ax2+bx+2>0的解集是(-12,13),则a-b的值等于______ 发布时间:2017-05-06 12:21 │ 来源:www.tikuol.com 题型:填空题 问题: 不等式ax2+bx+2>0的解集是(-12,13),则a-b的值等于______.
题型:填空题 请根据图回答下列问题。它们属于______门,它们的主要特征是体表具有坚硬的_______和_______的附肢,它又可以分为四个纲,其中的①②③④分别属于______纲、_______纲、________纲和______纲。 查看答案
题型:填空题 —You were out when I dropped by your house. —Oh, I ______ for a friend from England at the airport. [ ]A. was waitingB. had waited C. am waiting D. have waited 查看答案