山东省济南市高新区2021-2022学年八年级上学期期中考试数学试题

2021至2022学年第一学期期中学业水平测试高新初中数学八年级参考答案及评分标准一、选择题题号123456789101112答案CDBCCBDBBAAC二、填空题:（本大题共6个小题，每小题4分，共24分．）13．14．15．-116．117．18．Oxy三、解答题:（本大题共12个小题，共78分．解答应写出文字说明、证明过程或演算步骤．）19．（本题6分）解：原式··································································································4分···············································································································6分20．（本题6分）解：原式······························································································4分·····································································································6分21．（本题6分）解：（1），·······································································································3分（2），······································································································6分22．（本题8分）解：（1）如图所示 ·································································3分答案为：4······························································································4分（2）答案为：································································································5分（3）为轴上一点，的面积为4，·····························································································6分点的横坐标为：或，故点坐标为：或····························································································8分23．（本题8分）解：（1）答案为：···················································································2分（2）答案为：·····························································································4分（3）当时办会员卡：（元，不办会员卡：（元··································································6分，办会员卡更合算··································································································8分24．（本题10分）解：（1）当时，，则·····························································2分 把代入得，解得··················································4分（2）观察图象可知，不等式的解集是························································6分（3）当最大时，与、共线．由题意得，直线与轴的交点即为所求·········································································8分当时，可得，解得，故点坐标为······································································································10分24．（本题10分）解：解：（1）答案为：························································································2分（2）答案为：·······························································································5分（3）·····························································7分································································································8分················································································································10分26．（本题12分）解：（1）设与的函数关系式是······································································1分点，在函数的图象上， ，解得，即与的函数关系式是······································································3分当时，，即两人相遇地点与地的距离是··················································································4分（2）设线段对应的与的函数关系式是，点在函数的图象上····································································5分，解得····················································································································6分即线段对应的与的函数关系式是···························································7分（3）由题意得：·························································8分解得······································································································9分由题意得，甲到地的时间为：不符合题意·······································································································10分甲、乙两人相距5千米时，········································································11分解得·····················································································································12分即经过小时或小时时，甲、乙两人相距5千米．27．（本题12分） 解：（1）直线的解析式为，令，解得，······························································································1分令，解得····················································································3分点的坐标为，点的坐标为．（2）联立，得··········································································4分解得：··························································································5分故点································································································6分··························································································7分·······················································································································8分（3）存在·····················································································································9分点的坐标为或或··································································12分