# 备料SAT：SAT数学真题解析四则

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现在有很多的小伙伴都在备考SAT考试，这因为SAT考试成绩，在申请美国大部分大学时都是必须提供的，所以SAT考试现在很受留学生们的关注，大家都知道SAT数学对于同学们来说是比较容易拿分的一项，但想拿高分，平时还是要多加练习，那么今天小编就给大家带来SAT数学真题解析四则，希望大家在平时备考的时候就要多加练习，让自己熟能生巧，考试不慌。

一、真题四则：

1. If f(x) = (x + 2) / (x-2) for all integers except x=2, which of the following has the greatest value?

A. f(-1)

B. f(0)

C. f(1)

D. f(3)

E. f(4)

2. If n ≠ 0, which of the following must be greater than n?

I 2n

II n*n

III 2 - n

A. I only

B. II only

C. I and II only

D. II and III only

E. None 3. After being dropped a certain ball always bounces back to 2/5 of the height of its previous bounce. After the first bounce it reaches a height of 125 inches. How high (in inches) will it reach after its fourth bounce?

A. 20

B. 15

C. 8

D. 5

E. 3.2

4. n and p are integers greater than 1

5n is the square of a number

75np is the cube of a number.

The smallest value for n + p is

A. 14

B. 18

C. 20

D. 30

E. 50

二、答案解析：

Explanation:

You can solve this by back solving – substitute the answer choices in the expression and see which gives the greatest value.sat

A (-1 + 2) / (-1-2) = -2 / 2 = -1;

B (0 + 2) / (0-2) = 2/ -2 = -1;

C (1 + 2) / (1-2) = 3/-1 = -3;

D (3 + 2) / (3-2) = 5/1 = 5;

E (4+ 2) / (4-2) = 6/2 = 3

If you had just chosen the largest value for x you would have been wrong. So although it looks a long method, it is actually quick and accurate since the numbers are really simple and you can do the math in your head.

Explanation:

Remember that n could be positive negative or a fraction. Try out a few cases: In case I, if n is -1, then 2n is less than n. In case II, if n is a fraction such as ? then n2 will be less than n. In case III, if n is 2, then 2-n = 0, which is less than n. Therefore, none of the choices must be greater than n

Explanation:

If after each bounce it reaches 2/5 of the previous height, then after the second bounce it will reach 2/5 x 125. After the third it will reach 2/5 x 2/5 x 125. After the fourth it will reach 2/5 x 2/5 x 2/5 x 125. This cancels down to 2 x 2 x 2 = 8

Explanation:

The smallest value for n such that 5n is a square is 5. 75np can now be written as 75 x 5 x p. This gives prime factors.... 3 x 5 x 5 x 5 x p To make the expression a perfect cube, p will have to have factors 3 x 3 , and hence p =9 n + p = 5 + 9 = 14.

以上就是针对SAT数学题的相关知识，希望大家平时多加练习，如果想了解更多关于SAT真题数学解析的内容，请多多关注本网站，也可以添加微信号kewo11。  ## 联系我们

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