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标题: 请教两题数学 没事请进… [打印本页]

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作者: ken92    时间: 2008-1-11 16:19
标题: 请教两题数学 没事请进…

The rate of a certain chemical is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concentration of chemical B present. If the concentration of chemical B is increased by 100 percent, which of the following is closest to the percent change in the concentration of chemical A required to keep the reaction rate unchanged?
                

 

Ans: 40% increase
                

请问…这题是甚么意思啊??

 

2)

In the x-y plane, does the line with equation y= 3x+2 contain the point (r,s)??

(1)    (3r+2-s)(4r+9-s)= 0

(2)    (4r-6-s)(3r+2-s)= 0

 

Ans: C

我认为这题是E耶??

大家认为呢??

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作者: cookercai    时间: 2008-1-11 17:50

1，不知道你要问什么，问题是which of the following is closest ，所以最好你比较一下几个选项，题目意思很清楚啊，某个咚咚和A的浓度的平方成正比，和B的浓度成反比。

2，1+2连立，成立的条件只能是3r+2-s=0，所以y=3x+2肯定成立

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作者: boston8899    时间: 2008-1-11 22:52
Problem 1: 2^(1/2)-1 is about 40%

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作者: boston8899    时间: 2008-1-11 22:54
Problem 2: equation 1 - 2 ==> on the line.

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