山东省济宁市嘉祥县2017-2018学年七年级数学下学期期末学业水平测试试题2017-2018学年度第二学期期末学业水平测试七年级数学试题参考答案及评分标准一、选择题:(本大题共10个小题.每小题3分,共30分.)1.A2.C3.B4.D5.C6.D7.A8.B9.D10.C二、填空题(本题5个小题,每小题3分,共15分.)11.120°12.5413.14.2115.4三、解答题:(本大题共7小题,共55分)16.(每小题4分,共8分)(1)解法1:用代入消元法解:②152①1223yxyx..............................................................1分由②,得y=15-2x.③把③代入①,得3x-2(15-2x)=12.解这个方程,得x=6............................................................2分把x=6代入③,得y=3.........................................................3分所以这个方程组的解是.3,6yx..................................................4分解法2:用加减消元法解:②152①1223yxyx...............................................................1分②2,得4x+2y=30③①+③,得7x=42解这个方程,得x=6................................................................2分把x=6代入②,得y=3..........................................................3分所以这个方程组的解是.3,6yx....................................................4分学校-班级姓名考场考号……………………………..……………………密…………………….…….…………….封………………………..……………..线…………………………………………………………(2)解:去分母,得)23(315)5(5xx去括号,得xx6915255移项,得2591565xx合并同类项,得19x系数化为1,得19x.................................3分这个不等式的解集在数轴上的表示如图所示..............4分17.(本小题6分)(1)(-3,-1)............................................................2分(2)如图,描出点N并画出四边形BCMN............................................4分解法1(补全法):S=432121211621542167=6131042=22..............................................................................6分解法1图解法2图解法2(分割法):如图2S=432112212116215421=10+3+1+2+6=22..............................................................................6分18.(本题7分)解:(1)8、30%、14、35%...........................................................4分(2)如图,补全频数直方图如下:.......................................................6分(3)800×35%=280.答:估计参加这次比赛的800名学生中成绩“优”等的约有280人........7分19.(本题7分)(每空1分)∠BFE两直线平行,内错角相等∠2=∠BFE等式的性质∠AFC等量代换同位角相等,两直线平行20.(本题7分)解:(1)①②③................................................................................................3分(2)设长方形的长、宽各是xcm,ycm,由题意列方程组,得yxyx5)5(225..............................................5分解这个方程组,得34325yx...................................................6分答:长方形的长、宽各是325cm,34cm.............................................................7分21.(本题8分)解:(1)﹣5<x<5x>5或x<﹣5......................................................2分(2)﹣m<x<mx>m或x<﹣m................................................4分(3)|x﹣3|<5,∴﹣5<x﹣3<5,∴-2<x<8;...................................................................................................6分(4)|x﹣5|>3,∴x﹣5>3或x﹣5<﹣3,∴x>8或x<2.................................................................................