练习册

  • 练习册
  • 试题
    19．计算:． [关键词]分式的化简 [答案]解:原式= = = = 11先化简.再求值:.其中． [关键词]分式的运算 [答案] 原式= = = 当时.原式=． 12 先化简.再求值:.其中 [关键词]分式运算.实数运算 [答案] 13下表为抄录北京奥运会官方票务网公布的三种球类比赛的部分门票价格.某公司购买的门票种类.数量绘制的统计图表如下: 依据上列图表.回答下列问题: (1) 其中观看足球比赛的门票有 张,观看乒乓球比赛的门票占全部门票的 %, (2) 公司决定采用随机抽取的方式把门票分配给100名员工.在看不到门票的条件下.每人抽取一张(假设所有的门票形状.大小.质地完全相同且充分洗匀).问员工小华抽到男篮门票的概率是 , (3) 若购买乒乓球门票的总款数占全部门票总款数的.求每张乒乓球门票的价格. [关键词]频率估计概率.直方图.分式方程 [答案](1)50.20 (2) (3)依题意.有= ． 解得x ≈530 ． 经检验.x =530是原方程的解． 答:每张乒乓球门票的价格约为530元． 14 化简: [关键词]分式运算 [答案] 解:原式=···················································· 2分 =···························································································································································· 4分 =1． 5分 15计算: [关键词]分式运算 [答案] 解:原式=····································································· 2分 =················································································ 3分 ··············································································· 4分 ········································································································· 5分 162009湖北省荆门市)已知x=2+.y=2.计算代数式的值． [关键词]分式运算 [答案] 解:＝ ＝＝························································································· 4分 当x＝2+.y＝2-时.＝-4··································· 6分 17先化简.再求值:.其中． [关键词]分式运算 [答案]解:原式= =． 将代入得:原式=． 18． [关键词]分式运算 [答案]原式． 19 化简:·． [关键词]分式运算 [答案]原式=·=． 20先化简:.当时.请你为任选一个适当的数代入求值． [关键词]分式运算.最简分式 [答案]原式= = = 2120．先化简.再求值:. 其中． [关键词]分式化简 [答案]20．解:原式································ 2分 ······························································································ 3分 ··········································································································· 4分 ·················································································································· 5分 把 ··························································· 6分 22求代数式的值:.其中． [关键词]分式的化简与求值 [答案]解:原式= = = = 当时 上式 23先化简.再求值: +÷.其中x=． [关键词]分式.化简求值 [答案]解:原式= = = = = 当x=时.原式= =1- 24先化简.再求值: .其中 [关键词]分式 [答案]解: =························································································· 3分 ······················································································································· 4分 当时.原式···················································································· 5分 ······························································································· 6分 25先化简.然后从中选取一个你认为合适的数作为x的值代入求值． [关键词]分式的化简求值 [答案] 【查看更多】

     

    题目列表(包括答案和解析)

    (2009年上海市)19．计算：．

    查看答案和解析>>

    (2009年上海市)已知函数21世纪教育网 -- 中国最大型、最专业的中小学教育资源门户网站，那么21世纪教育网 -- 中国最大型、最专业的中小学教育资源门户网站        ．

    查看答案和解析>>

    (2009年上海市)19．计算：．

    查看答案和解析>>

    2009年11月4日，上海市人民政府新闻办宣布上海迪斯尼项目报告已获国家有关部门核准．相应的周边城市效应也随即带动，某周边城市计划开通至上海的磁悬浮列车，列车走完全程包含启动加速、均匀运行、制动减速三个阶段，已知磁悬浮列车从启动加速到稳定匀速运行共需200秒，在这段时间内的相关数据如表所示：
    时间 t（秒） 0   50  100   150  200
     速度V（米/秒）  0  30  60  90  120
     路程s（米）  0  750  3000  6750  12000
    （1）请你在一次函数、二次函数和反比例函数中选择合适的函数来分别表示在加速阶段（0≤t≤200）速度v与时间t的函数关系，路程s与时间t的函数关系．
    （2）最新研究表明，此种列车的稳定运行速度可达180米/秒，为了检测稳定运行时各项指标，在列车达到这一速度后至少要运行100秒，才能收集全相关数据．若在加速过程中，路程、速度随时间的变化关系任然满足（1）中的函数关系式，并且制动减速所需路程与启动加速的路程相同，根据以上要求，至少要建多长的轨道才能满足实验检测要求？

    查看答案和解析>>

    2009年11月4日，上海市人民政府新闻办宣布上海迪斯尼项目报告已获国家有关部门核准．相应的周边城市效应也随即带动，某周边城市计划开通至上海的磁悬浮列车，列车走完全程包含启动加速、均匀运行、制动减速三个阶段，已知磁悬浮列车从启动加速到稳定匀速运行共需200秒，在这段时间内的相关数据如表所示：
    时间 t（秒）0  50 100  150 200
     速度V（米/秒） 0 30 60 90 120
     路程s（米） 0 750 3000 6750 12000
    （1）请你在一次函数、二次函数和反比例函数中选择合适的函数来分别表示在加速阶段（0≤t≤200）速度v与时间t的函数关系，路程s与时间t的函数关系．
    （2）最新研究表明，此种列车的稳定运行速度可达180米/秒，为了检测稳定运行时各项指标，在列车达到这一速度后至少要运行100秒，才能收集全相关数据．若在加速过程中，路程、速度随时间的变化关系任然满足（1）中的函数关系式，并且制动减速所需路程与启动加速的路程相同，根据以上要求，至少要建多长的轨道才能满足实验检测要求？

    查看答案和解析>>


    同步练习册答案