七年级数学期末模拟卷（参考答案）【江苏南京】七年级数学期末模拟卷（江苏南京专用）-学易金卷：2023-2024学年初中上学期期末模拟考试.docx

2023-2024学年江苏南京上学期期末模拟考试

七年级数学

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C

9．5.5×104 10．6 11．36

12．1 13．﹣4 14．4

15．±1或﹣3 16.x-614=x-6-4.55

18．198

19．（8分）

解：（1）原式=3

=(31

＝9+5

＝14；··············································································4分

（2）原式=

=-

＝﹣8．·············································································8分

20．（6分）

解：（1）去括号得：4x+1＝6﹣2x，

移项合并得：6x＝5，

解得：x=56；

（2）解：去分母，得：2（2x+1）﹣（x﹣1）＝6，

去括号，得：4x+2﹣x+1＝6，

移项，得：4x﹣x＝6﹣2﹣1，

合并同类项，得：3x＝3，

系数化为1，得：x＝1．·······························································6分

21．（6分）

解：原式＝﹣x2﹣y+4x+2x2﹣4x﹣2y

＝x2﹣3y，··········································································3分

当x＝﹣3，y＝﹣1时，

原式＝（﹣3）2﹣3×（﹣1）＝9+3＝12．···············································6分

22．（8分）

解：（1）如图所示：

······························6分

（2）在这个几何体上再添加一些小正方体，并保持俯视图和左视图不变，最多可以再添加3个小正方体，

故答案为：3．·········································································8分

23．（6分）

解：（1）设商场第一次购进x套运动服，

由题意得：680002x

解这个方程，得x＝200．

经检验，x＝200是所列方程的根．

2x+x＝2×200+200＝600．

答：商场两次共购进这种运动服600套．·················································3分

（2）第一批运动服的进价

第二批运动服的进价

设每套运动服的售价是x元，

由题意得：400（x﹣170）﹣200（x﹣160）＝12000，

解得：x＝240

故答案为：240．······································································6分

24．（6分）

解：如图所示，

（1）线段AD即为所求；·······························································2分

（2）AC=2

∵AC2＝20，CD2＝5，AD2＝25，

∴AC2+CD2＝AD2

∴△ACD为直角三角形；

故答案为：25、直角三角形．···························································4分

（3）∵AD∥BC，

∴∠BAC＝∠ACD＝90°，

∵E为BC的中点，

∴AE=12BC=1

故答案为：52．·········································································6

25．（6分）

解：（1）如图1所示：

∵AC＝AB+BC，AB＝6cm，BC＝4cm

∴AC＝6+4＝10cm

又∵D为线段AC的中点

∴DC=12AC=12

∴DB＝DC﹣BC＝6﹣5＝1cm·······················································2分

（2）如图2所示：

设BD＝xcm

∵BD=14AB

∴AB＝4BD＝4xcm，CD＝3BD＝3xcm，

又∵DC＝DB+BC，

∴BC＝3x﹣x＝2x，

又∵AC＝AB+BC，

∴AC＝4x+2x＝6xcm，

∵E为线段AB的中点

∴BE=12AB=12×

又∵EC＝BE+BC，

∴EC＝2x+2x＝4