一、选择题(本大题共8个小题,每小题4分,共32分,每小题均有四个选项,其中只有一项符合题目要求,答案涂在答题卡上)
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A . 了解一叠钞票中有没有假钞
B . 调查神州17号载人飞船零部件的情况
C . 调查一批圆珠笔芯的使用寿命
D . 调查班上同学早餐是否有喝牛奶的习惯
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A . 过两点有且只有一条直线
B . 多项式
的次数是5
C . 用一个平面去截三棱柱,截面可能是六边形
D . 连接两点的线段叫做这两点间的距离
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8.
(2024七上·邛崃期末)
某电影院所有大厅可容纳的人数相同,所有小厅可容纳的人数也相同。2个大厅和1个小厅共可同时容纳1960人观影;1个大厅和2个小厅共可同时容纳1460人观影.如果设一个大厅可同时容纳
y人观影,由题意列出的方程正确的是( )
二、填空题(本大题共5个小题,每小题4分,共20分,答案写在答题卡上)
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10.
(2024七上·邛崃期末)
冰箱启动时内部的温度为6℃,在冰箱的降温范围内,如果每一小时冰箱内部的温度降低4℃,那么2小时后冰箱内部的温度为
℃.
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12.
(2024七上·邛崃期末)
神州17号载人飞船已于2023年10月26日上午11时14分成功发射.上午11时14分时钟上时针与分针的夹角是
.
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13.
(2024七上·邛崃期末)
某商店出售两件衣服,每件售240元,其中一件亏本20%,而另一件盈利20%,则这两件衣服在这次销售中的利润是
元.
三、解答题(本大题共5个小题,共48分,解答过程写在答题卡上)
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(1)
计算:
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(2)
解方程:
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmfrac%3E%3Cmrow%3E%3Cmn%3E4%3C%2Fmn%3E%3Cmi%3Ey%3C%2Fmi%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E6%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmfrac%3E%3Cmrow%3E%3Cmn%3E3%3C%2Fmn%3E%3Cmi%3Ey%3C%2Fmi%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmath%3E)
, 并判断所求出的未知数的值是否是原方程的解,请写出判断过程.
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(1)
求
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%A0%3C%2Fmo%3E%3Cmi%3EA%3C%2Fmi%3E%3Cmi%3EO%3C%2Fmi%3E%3Cmi%3EM%3C%2Fmi%3E%3C%2Fmath%3E)
的度数;
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16.
(2024七上·邛崃期末)
2023年,成都市积极响应教育部关于开展课后服务的号召,各校给学生提供了丰富多彩的课后活动.其中某校开展了以下体育项目:篮球,乒乓球,足球和羽毛球.该校每个学生都只选择参加其中一项活动.某调查组为了解该校选择各项体育活动的学生人数,随机抽取了部分学生进行调查,并将获得的数据进行了整理,绘制出了以下两幅不完整的统计图:
![](//tikupic.21cnjy.com/2024/02/22/7c/03/7c039d87004dfb302ca177dd5fe20f31_415x146.png)
根据图中提供的信息,回答下列问题:
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(1)
该调查组本次调查的学生人数是人,并补全条形统计图;
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(2)
选择足球项目的人数在扇形统计图中对应的圆心角度数为;
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(3)
若该学校有学生2400人,请你估计该学校学生选择篮球项目的人数约有多少人?
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(1)
若
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3EE%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmath%3E)
, 求线段
DF的长;
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(2)
若线段CE的长恰好等于线段DF的一半,求线段CE的长;
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(3)
如图2,取线段DE的中点M , 线段CF的中点N , 求线段MN的长.
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18.
(2024七上·邛崃期末)
乘坐滴滴快车是一种便捷的出行方式,其计价规则如下表:
计费项目 | 里程费 | 时长费 | 远途费 |
单价 | 1.6元/公里 | 0.4元/分钟 | 0.6元/公里 |
注:车费由里程费、时长费、远途费三部分构成,其中里程费按行车的实际里程计算;时长费按行车的实际时间计算;远途费的收取方式为:行车里程8公里以内(含8公里)不收远途费,超过8公里的,超出部分每公里另加收0.6元. |
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(1)
若张老师乘坐滴滴快车,行车里程为5公里,行车时间为8分钟,则需付车费多少元;
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(2)
若刘老师乘坐滴滴快车,行车里程为m公里,行车时间为n分钟,则刘老师应付车费多少元;
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(3)
小聪与小敏各自乘坐滴滴快车,乘车里程分别为7.5公里与9公里,并且两人下车时所付车费相同,请问小聪的行车时间与小敏的行车时间有何关系?
四、填空题(本大题共5个小题,每小题4分,共20分,答案写在答题卡上)
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20.
(2024七上·邛崃期末)
一个几何体由若干大小相同的小立方块搭成,下图分别是从正面、上面看到的形状图,则搭成这个几何体的小立方块最多有
个.
![](//tikupic.21cnjy.com/2024/02/22/34/cb/34cbbd7c476502319e7065db6ad3be63_220x88.png)
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21.
(2024七上·邛崃期末)
我们知道无限循环小数是有理数,有理数包括整数和分数,任何一个无限循环小数都可以写成分数或整数的形式,应该怎样写呢?我们以无限循环小数
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmover%3E%3Cmrow%3E%3Cmn%3E6%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%C2%B7%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmover%3E%3C%2Fmath%3E)
为例进行说明:设
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmover%3E%3Cmrow%3E%3Cmn%3E6%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%C2%B7%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmover%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmi%3Ex%3C%2Fmi%3E%3C%2Fmath%3E)
, 由
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmover%3E%3Cmrow%3E%3Cmn%3E6%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%C2%B7%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmover%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmn%3E6%3C%2Fmn%3E%3Cmover%3E%3Cmrow%3E%3Cmn%3E6%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%C2%B7%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmover%3E%3C%2Fmath%3E)
;可知
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E6%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmover%3E%3Cmrow%3E%3Cmn%3E6%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%C2%B7%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmover%3E%3C%2Fmath%3E)
, 而
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmtext%3E6%3C%2Fmtext%3E%3Cmtext%3E.%3C%2Fmtext%3E%3Cmover%3E%3Cmrow%3E%3Cmn%3E6%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%C2%B7%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmover%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmtext%3E6%3C%2Fmtext%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmtext%3E0%3C%2Fmtext%3E%3Cmtext%3E.%3C%2Fmtext%3E%3Cmover%3E%3Cmrow%3E%3Cmn%3E6%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%C2%B7%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmover%3E%3C%2Fmath%3E)
, 所以
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E6%3C%2Fmn%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmi%3Ex%3C%2Fmi%3E%3C%2Fmath%3E)
, 解得
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmfrac%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3C%2Fmath%3E)
, 于是得
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmover%3E%3Cmrow%3E%3Cmn%3E6%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%C2%B7%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmover%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmfrac%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3C%2Fmath%3E)
. 按此方法,将
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmover%3E%3Cmrow%3E%3Cmn%3E4%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%C2%B7%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmover%3E%3C%2Fmath%3E)
写成分数(或整数)的形式是
,将
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E5%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmover%3E%3Cmrow%3E%3Cmn%3E7%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%C2%B7%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmover%3E%3Cmover%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%C2%B7%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmover%3E%3C%2Fmath%3E)
写成分数(或整数)的形式是
.
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22.
(2024七上·邛崃期末)
古代数学问题趣题,如图,一个瓶子的容积为1200 cm
3 , 瓶内装着一些溶液.当瓶子正放时,瓶内溶液恰好为瓶子圆柱体部分,液体高度为24 cm,当瓶子倒放时,空余部分圆柱体的高度为6 cm.则瓶内溶液的体积为
cm
3 .
![](//tikupic.21cnjy.com/2024/02/22/30/71/3071072bd2d71852c6ba86b235fe8f20_178x102.png)
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23.
(2024七上·邛崃期末)
如图,点
G为直线
EF上一点,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%A0%3C%2Fmo%3E%3Cmi%3EA%3C%2Fmi%3E%3Cmi%3EG%3C%2Fmi%3E%3Cmi%3EB%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E4%3C%2Fmn%3E%3Cmn%3E5%3C%2Fmn%3E%3Cmo%3E%C2%B0%3C%2Fmo%3E%3C%2Fmath%3E)
, 将
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%A0%3C%2Fmo%3E%3Cmi%3EA%3C%2Fmi%3E%3Cmi%3EG%3C%2Fmi%3E%3Cmi%3EB%3C%2Fmi%3E%3C%2Fmath%3E)
绕点
G逆时针旋转,当射线
GA与射线
GE重合时停止旋转;在旋转过程中,射线
GC始终平分
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%A0%3C%2Fmo%3E%3Cmi%3EA%3C%2Fmi%3E%3Cmi%3EG%3C%2Fmi%3E%3Cmi%3EE%3C%2Fmi%3E%3C%2Fmath%3E)
;当
GB ,
GC ,
GE三条射线中有一条是另外两条射线所成夹角的平分线时,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%A0%3C%2Fmo%3E%3Cmi%3EA%3C%2Fmi%3E%3Cmi%3EG%3C%2Fmi%3E%3Cmi%3EF%3C%2Fmi%3E%3C%2Fmath%3E)
的度数为
.
![](//tikupic.21cnjy.com/2024/02/22/9d/d2/9dd280b59b54f2b2e47e009ba9ebd942_228x114.png)
五、解答题(本大题共3个小题,共30分,解答过程写在答题卡上)
-
24.
(2024七上·邛崃期末)
【阅读】有一种整式处理器,能将二次多项式处理成一次多项式,处理方法是:将二次多项式的二次项的未知数次数二次变为一次,再将其二次项的系数乘以2保留,将二次多项式的一次项去掉未知数只保留其系数,将二次多项式的常数项去掉.例如:二次多项式
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EA%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E3%3C%2Fmn%3E%3Cmsup%3E%3Cmrow%3E%3Cmi%3Ex%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmath%3E)
, 二次多项式
A经过处理器处理得到一次二项式
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EB%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E%28%3C%2Fmn%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmo%3E%C3%97%3C%2Fmo%3E%3Cmn%3E3%3C%2Fmn%3E%3Cmn%3E%29%3C%2Fmn%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E6%3C%2Fmn%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmath%3E)
.
【应用】若关于x的二次多项式A经过处理器处理得到一次二项式B , 根据以上方法,解决下列问题:
-
(1)
若
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EA%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E6%3C%2Fmn%3E%3Cmsup%3E%3Cmrow%3E%3Cmi%3Ey%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E6%3C%2Fmn%3E%3Cmi%3Ey%3C%2Fmi%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmath%3E)
, 则
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EB%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3C%2Fmath%3E)
;
-
(2)
若
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EA%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E4%3C%2Fmn%3E%3Cmsup%3E%3Cmrow%3E%3Cmi%3Ey%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E%28%3C%2Fmn%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmi%3Ey%3C%2Fmi%3E%3Cmn%3E%29%3C%2Fmn%3E%3C%2Fmath%3E)
, 求关于
y的方程
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EB%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmtext%3E0%3C%2Fmtext%3E%3C%2Fmath%3E)
的解;
-
(3)
【延伸】
已知
, A是关于y的二次多项式,若B是A经过处理器得到的关于y的一次二项式,求关于y的方程
的解.
-
-
(1)
如图1,已知点
M ,
N是线段
CD上两点,且
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3ED%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E6%3C%2Fmn%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3EM%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E4%3C%2Fmn%3E%3Cmi%3ED%3C%2Fmi%3E%3Cmi%3EN%3C%2Fmi%3E%3C%2Fmath%3E)
, 点
E和点
F分别是线段
CN和线段
DM的中点.若线段
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3ED%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E4%3C%2Fmn%3E%3Cmtext%3E%E2%80%89%3C%2Fmtext%3E%3Cmtext%3Ec%3C%2Fmtext%3E%3Cmtext%3Em%3C%2Fmtext%3E%3C%2Fmath%3E)
, 分别求线段
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3EM%3C%2Fmi%3E%3C%2Fmath%3E)
,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3ED%3C%2Fmi%3E%3Cmi%3EN%3C%2Fmi%3E%3C%2Fmath%3E)
,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EE%3C%2Fmi%3E%3Cmi%3EF%3C%2Fmi%3E%3C%2Fmath%3E)
的长;
-
(2)
已知
OM ,
ON是从
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%A0%3C%2Fmo%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3EO%3C%2Fmi%3E%3Cmi%3ED%3C%2Fmi%3E%3C%2Fmath%3E)
的顶点发出的两条射线,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%A0%3C%2Fmo%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3EO%3C%2Fmi%3E%3Cmi%3ED%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E6%3C%2Fmn%3E%3Cmo%3E%E2%88%A0%3C%2Fmo%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3EO%3C%2Fmi%3E%3Cmi%3EM%3C%2Fmi%3E%3C%2Fmath%3E)
且
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%A0%3C%2Fmo%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3EO%3C%2Fmi%3E%3Cmi%3ED%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E4%3C%2Fmn%3E%3Cmn%3E4%3C%2Fmn%3E%3Cmo%3E%C2%B0%3C%2Fmo%3E%3C%2Fmath%3E)
, 射线
OE和射线
OF分别平分
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%A0%3C%2Fmo%3E%3Cmi%3EC%3C%2Fmi%3E%3Cmi%3EO%3C%2Fmi%3E%3Cmi%3EN%3C%2Fmi%3E%3C%2Fmath%3E)
,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%A0%3C%2Fmo%3E%3Cmi%3ED%3C%2Fmi%3E%3Cmi%3EO%3C%2Fmi%3E%3Cmi%3EM%3C%2Fmi%3E%3C%2Fmath%3E)
.
①如图2,若OM , ON均为
内的两条射线,且
, 求
的度数;
②如图3,若OM为
外的一条射线,且
, 则
▲ .
-
-
(1)
请直接写出
a ,
b的值:
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3Ea%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3C%2Fmath%3E)
,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3Eb%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3C%2Fmath%3E)
;
-
(2)
数轴上
a ,
b ,
x三个数所对应的点分别为
A、
B、
X , 且点
X是数轴上的任意点,点
A与点
X之间的距离用
AX表示,点
B与点
X之间的距离用
BX表示,请计算当
x分别为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmn%3E5%3C%2Fmn%3E%3C%2Fmath%3E)
, 0,2025时,代数式
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EA%3C%2Fmi%3E%3Cmi%3EX%3C%2Fmi%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmi%3EB%3C%2Fmi%3E%3Cmi%3EX%3C%2Fmi%3E%3C%2Fmath%3E)
的值,并指出当
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3EA%3C%2Fmi%3E%3Cmi%3EX%3C%2Fmi%3E%3Cmo%3E%2B%3C%2Fmo%3E%3Cmi%3EB%3C%2Fmi%3E%3Cmi%3EX%3C%2Fmi%3E%3C%2Fmath%3E)
的值最小时,点
X在数轴上的位置;
-
(3)
如果在数轴连续的整数点上依次有n个机器人,且相邻两个机器人之间的距离都是1个单位,同时数轴上有一个快递包裹分发点智能机器人,它能根据机器人的数量自动决策出快递包裹分发点的位置,使得每个机器人去取快递包裹的距离之和最小,请直接用含n的代数式表示这个最小值.