PREP模考的三道题...

famous8008

一:In the xy-coordinate plane, line L and line K intersect at the point (4;3). Is the product of thier slopes negative?
1) The product of the x-intersepts of lines L and K is positive
2) The product of the y-intersepts of lines L and K is negative 选C,为什么不选B?

二:Is the hundredths digit of the decimal d greater than 5?
1) The tenth digit of 10d is 7
2) The thoudsands digit of d/10 is 7  选D,没看懂题的意思,能帮忙翻译下吗?

三:If x and y are positive, which of the following must be greater than 1/根号(x+y)?

1,根号(x+y)/2x

2,(根号x+根号y)/(x+y)

3,(根号x-根号y)/(x+y)

A NONE

B 1 ONLY

C 2 ONLY

D 1AND 3

E 2 AND 3 答案选C,想问,为什么不选A?如果x和y都是1的情况呢?greater than 包括相等吗?

famous8008

8号要考了,自己顶一下,望有人来解答下~谢谢

JNash

1.画个图你就知道了
2.注意是个小数，他说的是十分位千分位。
3.把2 和原公式都平方以下。

JNash

感觉这些不怎么绕，你翻翻PREP破解把，有很多十分偏偏的话语……犹如荷马时代的诗篇……