24.解:(1)由题意,得:解得
················································ (2分)
∴····················································································· (3分)
(2)
∴··················································································· (5分)
∴
时,
有最大值为6.6. ····························· (7分)
∴(吨).
答:甲、乙两种水果的进货量分别为4吨和6吨时,获得的销售利润之和最大,最大利润是6.6万元. ························································································································ (8分)
23.解:分别过
作
于
于
过
作
于
则四边形
为矩形.
∴
在中,
∴·············································································································· (3分)
在中,
············································ (6分)
∴············································· (7分)
答:水深约为6.7米.·································································································· (8分)
(其它解法可参照给分)
22.解:(1)10,50;········································································································ (2分)
(2)解:解法一(树状图):
··········································································································································· (6分)
从上图可以看出,共有12种可能结果,其中大于或等于30元共有8种可能结果,因此(不低于30元)=
····························································································································· (8分)
解法二(列表法):
![]() 第二次 |
0 |
10 |
20 |
30 |
![]() |
|
10 |
20 |
30 |
10 |
10 |
|
30 |
40 |
20 |
20 |
30 |
|
50 |
30 |
30 |
40 |
50 |
|
····························································································································· (6分)
(以下过程同“解法一”)····················································································· (8分)
21.(1)935.7,859.0;······································································································ (4分)
(2)解:2004~2008移动电话年末用户逐年递增.
2008年末固定电话用户达803.0万户.······················································· (8分)
(注:答案不唯一,只要符合数据特征即可得分)
20.解:(1);·········································································································· (2分)
(2)答案不唯一,以下提供三种图案.
(注:如果花边图案中四个图案均与基本图案相同,则本小题只给2分;未画满四个“田”字格的,每缺1个扣1分.)
19.(1)解:原式= ·································································· (2分)
=······································································· (3分)
=.······························································································· (4分)
(2)解:原式=············································································ (2分)
=·························································································· (3分)
=1.·········································································································· (4分)
(3)解:移项,得配方,得
····················································· (2分)
∴∴
·································································· (4分)
(注:此题还可用公式法,分解因式法求解,请参照给分)
6.210 7.(9,0) 8.8 9.
10.
1.>
2.
3.答案不唯一,如
4.
5.30
26. 本题属于大综合题目,主要考查的知识点有一次函数、二次函数、方程组与平移、三角形的面积、三角形的相似等知识点.解决本题的关键是理顺各知识点间的关系,还要善于分解,化整为零,各个击破.
2009年山西省初中毕业学业考试试卷
数 学
26.(本题14分)如图,已知直线与直线
相交于点
分别交
轴于
两点.矩形
的顶点
分别在直线
上,顶点
都在
轴上,且点
与点
重合.
(1)求的面积;
(2)求矩形的边
与
的长;
(3)若矩形
从原点出发,沿
轴的反方向以每秒1个单位长度的速度平移,设移动时间为
秒,矩形
与
重叠部分的面积为
,求
关于
的函数关系式,并写出相应的
的取值范围.
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