2025年北京市平谷区九年级中考一模数学试卷(图片版,含答案)

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2025年北京市平谷区九年级中考一模数学试卷(图片版,含答案)

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平谷区 2024 年一模试卷评分标准
初 三 数 学
2025 年 4 月
一、选择题(本题共 16 分,每小题 2 分)
题号 1 2 3 4 5 6 7 8
答案 D B B C C A A D
二、填空题(本题共 16 分,每小题 2 分)
题号 9 10 11 12 13 14 15 16
答案 x 5 a(x +1() x 1) x =1 50° > 96 5 6;4
2
三、解答题(共 68 分,第 17—19 题,每题 5 分,第 20-21 题,6 分,第 22 题,5 分,第 23 题,6 分,第 24—25 题,
每题 5 分,第 26 题 6 分;第 27—28 题,每题 7 分)解答应写出文字说明、演算步骤或证明过程.
0
3tan 30 ( 2025) + 2 12
17.解:
3
=3 1+ 2 2 3
3 ····················································································4
=1- 3 ········································································································5
(2 x 1)>x 3

x 14
< 2x
18.解不等式组: 3
x 1
解①得 ····························································································································· 2
x 2
解②得 ······························································································································ 4
1 x 2 ·································································································5
19.先化简,再求值:
(2 x 2y)+ 2x
x 2 2xy + y2
2x 4y + 2x
=
(x-y)2 ························································································································· 2
(4 x y)
=
(x y)2 ································································································································· 3
4
=
x y ······································································································································· 4
x y = 2,
4
原式 = = 2
2 ························································································································· 5
20.解:
(1)∵AE∥BF,AF∥BE
∴四边形 AFBE 是平行四边形 ···································································································· 1
∵矩形 ABCD
∴∠D=90°
∴∠DAE+∠AED=90°
∵∠DAE=∠BEC
∴∠BEC+∠AED=90° ················································································································· 2
∴∠AEB=90°
∴四边形 AFBE 是矩形 ················································································································ 3
(2)∵∠DAE=30°,∠D=90°,DE=1
∴AE=2
∵矩形 ABCD
∴∠BAD=90°,
∴∠BAE=60°
∵∠AEB=90°
∴∠ABE=30° ······························································································································ 5
∴AB=2AE=4
∵矩形 AFBE
∴EF=AB=4 ····································································································6
21. 解:设明明第一天领取 x 分钟,妹妹第一天领取了 y 分钟. ·································2
x =(1+50%)y

x =(1+50%)
2y 15 ·············································································································· 4
x = 30

y = 20 解得: ················································································································· 5
答:
明明第一天领取 30 分钟,妹妹第一天领取了 20 分钟 ·······································6
(方法不唯一,其他方法依步骤给分)
22.(1)∵函数 y=2x 过点(1,m)
∴m=2 ··········································································································1
∵函数 y=kx+3(k≠0)过点(1,2)∴k=-1 ·············································································· 2
y = x + 3 ······························································································································· 3
(2) a 2. ··············································································································· 5
23.(1)证明:连接 BD
∵AB 是直径
∴∠ADB=90° ································································································1
∵AB=BC,∠ADB=90°
∴AD=DC ······································································································································· 2
∵O 是 AB 的中点
∴OD∥BC
······················································································································································ 3
C
(2)过点 D 作 DH⊥AB 于点 H
D
AC = 4 5
AD = 2 5
A BH O
∵AB=BC=10
由勾股定理得:BD = 4 5
················································································4
∵∠ADB=∠DHA=90°
E
AD BD=AB DH
2 5 4 5=10 DH
∴DH=4
∴HO=3 ········································································································5
∵BE 是⊙O 的切线
∴∠ABE=90°
∵DH⊥AB
∴△DHO∽△EBO
3 5
=
4 BE
20
解得:BE =
3 ······························································································6
24.解(1)补全函数图象 ·············································································································· 2
脂肪氧化率(g/min)
0.7
0.6
0.5
0.4
0.3
0.2
0.1
O 45 50 55 60 65 70 75 80 85 90运动强度(%vo2max)
(2)①0.55(0.54-0.58 均可) ····································································································· 3
52 x 78(下限 51-53 之间,上限 77-79 之间均可)
② ·····································4
③ 8 ············································································································5
.
25.(1) m=__88____,n=__87___;
················································································· 2
(2) 补全频数分布直方图;
······················································································································································ 3
(3)乙;甲 ································································································································ 5
26.(1)当 a=1 时,
抛物线 y = x
2 2x +C
抛物线的对称轴为 x=1 ··············································································································· 1
点A( 1,y),B (m,y1 2 )
因为 y1 = y2
所以点 A 与点 B 关于 x=1 对称
∴m=3
··········································································································································· 2
(2)∵抛物线的对称轴为 x=a,······························································································ 3
情况 1:当 a>0 时
A( a,y1 )一定位于对称轴的左侧
x=a
A(-a,y ) A,1 (3a,y1)
4
2
a 2 4

3a 4 解得
a
此时,有 3 ············································································4
情况 2:情况 1:当 a<0 时
A( a,y1 )一定位于对称轴的右侧
x=a
a 2解 得 a 2
此时,有
-2 a<0
····························A··,··(·3·a·,···y··)···························A··(··-·a·,···y··)····································5 1 1
综上,
4
a 或-2 a<0 2
3 4
······················································································································································ 6
27.(1)
∵将线段 BC 绕着点 C 逆时针旋转β°得到线段 CD
∴CB=CD,∠BCD=β
180
∠CBD=
2 ..........................................1
180
+ =180
2
2 =180 E
..........................................2
(2)
C
1
结论:EG = BD
2 .........................................3
F G
依题意补全图形;.........................................4
证明: 取 BD 的中点 K,连接 CK、FK、EF. D
A B K
3
=
2
∴∠ABC=135°,∠BCD=90°
∵K 为 BD 中点
∴CK⊥BD
∵AE⊥DC
∴∠AEC=∠AKC=90°
∵点 F 是 AC 中点
∴FK=AF=FC=EF
∵BC=CD,∠BCD=90°
∴∠D=45°
∵∠AED=90°
∴∠EAD=45°
∴∠EFK=∠EFC+∠CFK
=2∠EAC+2∠CAD
=2∠EAD
=90°
∵AB=BC,F 为 AC 中点
∴BF⊥AC
∠BFG=90°
∴∠BFK=∠EFG
∵FB=FG
∴△EFG≌△KFB..........................................6
∴EG=BK
1
EG = BD
2 .....................................7
28.解:(1)A1B1,A3B3; ········································································································ 2
1 1
(0, 1+ 3)或(0, 1 3)
(2) 4 4 ············································································· 4
(3)2; ······································································································································· 5
2
2 1
1
x
–3 –2 –1 O 1 2 3
x
–3 –2 –1 O 1 2 3
–1
–1
–2
–2
–3 –3
3+ 13 3 + 39 1 13 3 39
( , )或( , )
8 8 8 8 ··························································· 7

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