2025-2026 学年第一学期学业水平质量监测题(卷)
八年级数学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)
题号 1 2 3 4 5 6 7 8 9 10
答案 C A C B D B A C D B
二、填空题(本大题共 5个小题,每小题 3分,共 15分)
11. 7答案不唯一,如 y=-x 12.(0,1) 13. 1640 14. 33 15.
5
三、解答题(本大题共 8个小题,共 55分)
16.(8分)计算:
(1 8)解: 32 3 64
2
2 4 2 4 ····························································3分
5 2 4;······························································· 4分
(2)解: 50 18
( 5 3)( 5 3)
2
5 2 3 2 5 3 ······················································ 7分
2
2 2。·································································8分
17.(5分)
2x 3y 42, ①
解:
3x y 3。 ②
方法一:由②得: y 3x 3。 ③··········································· 1分
将③代入①中,得 2x 3(3x 3) 42。······························2分
解得: x 3。···························································· 3分
将 x 3代入③中,得 y 3 3 3 12。····························4分
1
x 3,
所以原方程组的解是 ·········································5分
y 12。
方法二:由②×3得:9x 3y 9。 ③···································1分
由③+①,得11x 33。··················································2分
解得: x 3。···························································· 3分
将 x 3代入②中,得3 3 y 3。
解得: y 12。···························································4分
x 3,
所以原方程组的解是 ·········································5分
y 12。
(其他方法酌情给分)
18.(5分)
证明:∵∠A=∠B,
∴AD∥BC。····················1分
∴∠D=∠BFD。···············2分
∵∠1=∠2,
∴CE∥DF。····························································3分
∴∠C=∠BFD。·······················································4分
∴∠C=∠D。···························································5分
19.(8分)
解:(1) a =9, ·························································································1分
b =8,····································································· 3分
c =7.5;···································································5分
(2)答案不唯一,可以用不同方法进行分析评价,合理即可。
如用平均数、方差进行分析:使用 AI自习室前的平均数是 8.2分,方
差是 1.61;使用 AI 自习室后成绩的平均数是 8.45分,方差是 1.55。
可以看出,整体上,使用 AI自习室可以适当提高成绩,整体成绩的稳
定性也有所提高。·······················································8分
(也可以用四分位数、箱线图进行分析,还可以利用折线统计图进行分析)
2
20.(8分)
解:(1)方法一:根据套餐 A中每种馄饨的数量权重情况,可得套餐 A中的
1 3 3 3
定价应为:16 10 6 8 8.8元。··········2分
10 10 10 10
方法二:由题可得,每个鲜虾馄饨为 1.6元,每个香菇鲜肉馄饨为 1元,每个
白菜鲜肉馄饨为 0.8元,每个韭菜鲜肉馄饨为 0.6元。
根据套餐 A中每种馄饨的数量,可得套餐 A每碗馄饨的定价应为:
1.6 1 1 3 0.6 3 0.8 3 8.8元。····························· 2分
(2)设套餐 B中鲜虾馄饨和香菇鲜肉馄饨的个数分别为 x个和 y个。
············································································ 3分
x y 2 1 10,
由题可得:
1.6x y 0.8 2 0.6 1 11。
x y 7,
化简得: ··············································· 5分
1.6x y 8.8。
x 3,
解得: ···························································· 7分
y 4。
答:套餐 B中有 3个鲜虾馄饨和 4个香菇鲜肉馄饨。·········8分
21.(7分)
解:(1)24;·································································1分
(2)设 y=kx+b。······················································ 2分
25k b 2,
由题意得: ·········································· 4分
22k b 5。
k 1,
解得: ······················································· 6分
b 27。
∴一次函数表达式为 y=-x+27。·································· 7分
22.(7分)
解:① y 2.73x;································································· 2分
② y 3.28x 165;··························································4分
③ y 3.82x 489。························································· 6分
3
(2)500。····································································· 7分
23.(7分)
解:(1) 17 ;···································································· 2分
(2)①如图:
··························4分
② 2 2;································································· 6分
(3)答案不唯一,言之有理即可。如用网格解几何题解决的是可以用网
格画出的格点线段的相关问题,限制了解题的普适性。······ 7分
4姓
名
准考证号
2025-2026学年第一学期学业水平质量监测题(卷)
八年级数学
【温鉴提示】
1.试题共8页,计23题:总分使100分:答题时间90分钟。
2.答卷前,考生务必将自己的信息填写在试卷答题卡的相应住置。
3.答案全部在答题卡上完成,答在本试巷上元效。
一、选择题(本大题共10个小题,每小题3分,共30分。在每个小题给出的
四个选项中,只有一项符合题目要求,请选出并在答题卡上将该项涂黑)
下列各数中无理数是1
A.0
B.
C.2
D.4
2在平面直角坐标系中,点P的位置如图所示,则
点P关于x轴对称的点的坐标为
A.(1,-2)
B.(-1,-2)
321可
23
g.(-2,1)
D.(-1,2)
3.下列运算中正确的是
AV9-3=6
B.2W5+3V3=6v3
C.v12÷v2=6
D.(2+102=3
1,小明将两块相同的直角三角尺如图摆放画出了平行线,其依据是
A.同位角相等,两直线平行
B内错角相等,两直线平行
C同旁内伟互补,两直线平行
D.平行于同一条直线的两条直线平行
满足下列条件的AABC,不是直角三角形的是
A.AB=7,BC-24,AC-25
B.AB BC AC-3:4:5
C.∠A=∠B+∠C
D.∠A:∠B:∠C3:4:5
八年级数学试题第1页(共8页)
6.甲、乙、丙、丁四支排球队队员的身高侍况如图
身省am
所示,则身高最整齐的球队是
A.甲队
B.乙队
C.丙队
D.丁队
1伤
如图,一次函数y=x+b(k,b为常数,0)
甲乳乙卧丙队丁队
与y=x-2图象的交点坐标是(m,2),则关于
2
x,y的方程组
X-y=2
的解是
y-kx=b
2
A./x4
B.=2
C.J*=0
y=2
y=4
lv=2
D./*=2
y=0
8.下列说法中正确的是
A.小明所在班级学生的平均身高是1.66m,
小亮所在班毁学生的平均身高
是1.60m,小颖说“小亮一定比小明矮”
P已知A,B两家网站用户的日人均上网时间分别为2h和1h,这两家网
站所有用户的日人均上网时间为(2+1)÷2=1.5(h)
C.小军所在的篮球队队员身高的中位数是1.82m,他说“我身高1.84m,
我的身高在篮球队里是中等偏上的”
D,在统计学里,分组的方法有很多,其中较常用的方法是使“组内离差平
方和达到最大”
9物理活动中,小明探究了物质质量与体积的关系,得到甲、乙、丙三个实
心物体的质量m(单位:g)与(单位:cm)之间的关系如图所示p-件,
p表示密度),则下列说法正确的是
卡/g
丙
7
A甲物质的质量m随着其体积V的增加
而诚小
&随着体积的增加,乙物质的质量m
申
的变化是不的匀3的
C.6cm丙物质的质量为4g
D.丙物质的密度最大
6
810/cm
八年级数学试题第2页(共8页)