2011年四川省资阳市中考数学试题及答案(word版)(2)

=÷ ···························· 2分

x 4x 4

===

(x 4) 1(x 3)(x 3)÷ ························· 4分

x 4x 4x 4x 3× ··························· 5分 x 4(x 3)(x 3)

1

． ································· 6分 x 3

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18. (1) ∵四边形ABCD是平行四边形，

∴AB=CD，AB∥CD， ···························· 1分 ∴∠ABD=∠CDB． ····························· 2分 ∵AE⊥BD于E，CF⊥BD于F，∴∠AEB=∠CFD =90°． ············· 3分 ∴△ABE≌△CDF(A.A.S.)， ························· 4分 ∴BE=DF． ································ 5分 (2) 四边形MENF是平行四边形． ······················ 7分 19. (1) (x－1) ······························· 1分

(16x－64)(此空没有化简同样给分)． ··················· 2分 16x 64 0,

······························ 4分

16x 64 32.

(注：若只列出一个正确的不等式，得1分)

解得 4<x<6．∵ x为整数，∴x=5． ····················· 5分 因此需租用48座客车5辆．

(2) 租用48座客车所需费用为5×250=1250(元)，

租用64座客车所需费用为(5－1)×300=1200(元)， ·············· 6分 ∵ 1200<1250，∴ 租用64座客车较合算． ·················· 7分 因此租用64座客车较合算．

120. (1) PA处买到最低价格礼物=． ··························· 2分

3

(2) 作出树状图如下：

·················· 6分

由树状图可知：P购到最低价格礼物=∵

31

=， ····················· 7分 62

11

>，∴他的想法是正确的． ······················ 8分 23

(注：若判断了想法正确，但没有说理，得1分)

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21. (1) 连结OB、OF． ····························· 1分

∵A、B、C、D、E、F是⊙O的六等分点，

∴ AD是⊙O的直径， ··························· 2分 且∠AOB=∠AOF=60°， ··························· 3分 ∴ △AOB、△AOF是等边三角形． ······················ 4分 ∴AB=AF=AO，∴AB+AF = AD． ························ 5分 上时，PB+PF = PD；当P在BD 上时，PB+PD= PF；当P在DF 上时，PD+PF=PB.(2) 当P在BF

······································· 8分

(注：若只写出一个关系式且未注明点P的位置，不得分；若写出两个关系式且未注明点P的位置，得1分；若写出三个关系式且未注明点P的位置，得2分．) 22. (1) 把A(1，3)的坐标分别代入y=

m

、y=－x+b，可求得m=3，b=4． ······· 2分 x

3

，一次函数的解析式为y=－x+4． x

(2) 由(1)知，反比例函数的解析式为y=

∵ 直线MC⊥x轴于C，交直线AB于点N， ∴ 可设点M的坐标为(x，

3

)，点N的坐标为(x，－x+4)，其中，x>0． ····· 3分 x

又∵ MD⊥y轴于D，NE⊥y轴于E，∴ 四边形MDOC、NEOC都是矩形， ······ 4分 ∴ S1=x·

32

=3，S2=x·(－x+4)=－x+4x， ········