学校 姓名 班级___________ 座位号 ……装…………订…………线…………内…………不…………要…………答…………题……
一、选择题(共10小题,每小题3分,满分30分)ay use the contents or services of this article for
1.下列图形是轴对称图形的是( )
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A. B. C. D.
2.下列运算正确的是( )
A.(a+b)2=a2+b2 B.(﹣2a2b)3=﹣8a5b3 C.a6÷a3=a2 D.a3?a2=a5
3.若分式
的值为0,则x的值为( )
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A.﹣1 B.0 C.2 D.﹣1或2
4.点M(1,﹣2)关于y轴的对称点坐标为( )ay use the contents or services of this article for
A.(﹣1,2) B.(2,﹣1) C.(1,2) D.(﹣1,﹣2)
5.若3x=15,3y=3,则3x﹣y=( )ay use the contents or services of this article for
A.5 B.3
C.15 D.10
6.分解因式8a2﹣8ab+2b2结果正确的是( )
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A.2(2a﹣b)2 B.8(a﹣b)2 C.4(a﹣b)2 D.2(2a+b)2
7.某种病毒的直径约为0.0000000028米,该直径用科学记数法表示为( )ay use the contents or services of this article for
A.0.28×10﹣8米 B.2.8×10﹣10米 C.2.8×10﹣9米
D.2.8×10﹣8米
1
8.将一副直角三角尺如图放置,若∠AOD=20°,则∠BOC的大小为( )
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A.140° B.160°
C.170° D.150°
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9.如图,△ABC中,CD是AB边上的高线,BE平分∠ABC,交CD于点E,BC=8,DE=3,则△BCE的面积等于( )
A.11
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D.3
B.8 C.12
10.如图,AE,AD分别是△ABC的高和角平分线,且∠B=36°,∠C=76°,则∠DAE的度数为( )
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A.40° B.20° C.18° D.38°
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二、填空题(共6小题,每小题4分,满分24分) 11.使式子1+
12.已知正n边形的一个内角为135°,则边数n的值是__________. 13.方程
的解是__________.ay use the contents or services of this article foray use the contents or services of this article fo有意义的x的取值范围是__________.
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14.计算:(2x﹣1y3)2÷(x﹣3y)=__________.
ay use the contents or services of this article for15.如图所示,已知点A、D、B、F在一条直线上,AC=EF,AD=FB,要使△ABC≌△FDE,还需添加一个条件,这个条件可以是__________.(只需填一个即可)
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2
16.如图,△ABC中,AB=AC,AD平分∠BAC,点E是线段BC延长线上一点,连接AE,点C在AE的垂直平分线上,若DE=12cm,则△ABC的周长是__________.
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三、解答题(共9小题,满分66分)
17.请你从下列各式中,任选两式作差,并将得到的式子进行因式分解.4a2,(x+y)2,1,9b2.
ay use the contents or services of this article for18.化简:.
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19.如图,在平面直角坐标系中,函数y=x的图象l是第一、三象限的角平分线. 实验与探究:
由图观察易知A(0,2)关于直线l的对称点A′的坐标为(2,0),请在图中分别标明B(5,3)、C(﹣2,5)关于直线l的对称点B′、C′的位置,并写出它们的坐标:B′__________、C′__________; 归纳与发现:
结合图形观察以上三组点的坐标,你会发现:坐标平面内任一点P(m,n)关于第一、三象限的角平分线L的对称点P′的坐标为__________.
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