SAT声明
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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:
1.Correct Answer: D
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.
2.Correct Answer: E
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
3.Correct Answer: C
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
4.Correct Answer: A
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。
未经课窝SAT考试网书面许可,任何单位或个人不得转载、复制本网站内容;否则我方将依法追究法律责任。