中考数学得分专练20

中考数学得分专练20一、选择题（以下每小题均有A，B，C，D四个选项，其中只有一个选项正确，请把正确选项的字母选入该题的括号内，每小题4分，共20分）1．3的倒数是（）A．13B．13C．3D．32．据2006年末的统计数据显示，免除农村义务教育阶段学杂费的西部地区和部分中部地区的学生约有52000000名，这个学生人数用科学记数法表示正确的是（）A．65.210B．65210C．75.210D．80.52103．小明五次跳远的成绩（单位：米）是：3.6，3.8，4.2，4.0，3.9，这组数据的中位数是（）A．3.9米B．3.8米C．4.2米D．4.0米4．如图1-1所示，将长为20cm，宽为2cm的长方形白纸条，折成图1-2所示的图形并在其一面着色，则着色部分的面积为（）A．234cmB．236cmC．238cmD．240cm5．平面直角坐标系中有六个点(15)A，，533B，，(51)C，，522D，，533E，，522F，，其中有五个点在同一反比例函数图象上，不在这个反比例函数图象上的点是（）A．点CB．点DC．点ED．点F二、填空题（每小题3分，共30分）6．比较大小：23（填“，或”符号）7．分解因式：29x．8．方程122xx的解为x．9．如图2，ABC，，是O上三点，40ACB∠，则ABO∠等于度．10．在一次抽奖活动中，中奖概率是0.12，则不中奖的概率是．11．在ABC△中，若8AB，6BC，则第三边AC的长度m的取值范围是．图1-2图1-1图2ACO12．如图3，小亮从A点出发前进10m，向右转15，再前进10m，又向右转15，…，这样一直走下去，他第一次回到出发点A时，一共走了m．13．如图4，是甲、乙两地5月下旬的日平均气温统计图，则甲、乙两地这10天日平均气温的方差大小关系为：2S甲2S乙．14．如图5，正方形ABCD的边长为4，MNBC∥分别交ABCD，于点MN，，在MN上任取两点PQ，，那么图中阴影部分的面积是．15．如图6，某机械传动装置在静止状态时，连杆PA与点A运动所形成的O交于B点，现测得4cmPB，5cmAB．O的半径4.5cmR，此时P点到圆心O的距离是cm．三、解答题16．（本题满分7分）如图7，方格中有一条美丽可爱的小金鱼．（1）若方格的边长为1，则小鱼的面积为．（3分）（2）画出小鱼向左平移3格后的图形（不要求写作图步骤和过程）．（4分）图3A15°15°图412345678910161820222426283032乙地甲地图5ABCDMNPQ图6ABPO17．（本题满分8分）阅读对人成长的影响是巨大的，一本好书往往能改变人的一生．1995年联合国教科文组织把每年4月23日确定为“世界读书日”．图8是某校三个年级学生人数分布扇形统计图，其中八年级人数为408人，表（1）是该校学生阅读课外书籍情况统计表．请你根据图表中的信息，解答下列问题：（1）求该校八年级的人数占全校总人数的百分率．（2分）（2）求表（1）中AB，的值．（4分）（3）该校学生平均每人读多少本课外书？（2分）图书种类频数频率科普常识840B名人传记8160.34漫画丛书A0.25其它1440.06表（1）18．（本题满分10分）二次函数2(0)yaxbxca的图象如图9所示，根据图象解答下列问题：（1）写出方程20axbxc的两个根．（2分）（2）写出不等式20axbxc的解集．（2分）（3）写出y随x的增大而减小的自变量x的取值范围．（2分）（4）若方程2axbxck有两个不相等的实数根，求k的取值范围．（4分）图7图8八年级九年级38％七年级28％图9xy3322114112O一、填空题（每小题4分，共20分）1．B2．C3．A4．B5．B二、填空题（每小题3分，共30分）6．7．(3)(3)xx8．49．5010．0.8811．214m12．24013．14．815．7.5三、解答题16．（1）16···································································································3分（2）············································································4分17．（1）1283834％％％·········································································2分（2）8160.342400··················································································1分2400(840816144)600A··································································2分1(0.340.250.06)0.35B····································································3分A的值为600，B的值为0.35··········································································4分（3）408341200％··················································································1分240012002····························································································2分该校学生平均每人读2本课外书．18．（1）11x，23x··················································································2分（2）13x·······························································································2分（3）2x···································································································2分（4）2k···································································································4分