马上要考了急！几道prep数学

lmf0801 · 发表于 2010-8-21 11:22:21

1 The numbers 75 can be written as the sum of the squares of 3 different positive intergers What is the sum of these 3 intergers
17 16 15 14 13

2 Inx-yplane at what two points does graph of y=(x+a)(x-a)intersects the x-axis?
(1) a+b=-1 (2) the graph intersects the y-axis (0-6)

3 A certain library assess fines for overdue books as follow on the frist day that a book is overdue The total fine is 0.1$.For each addtional day that a book is overdue the total fine is either increased by 0.3 or doubled whichever result in the lesser amount that is the total fine for a book on forth day it is overdue
0.6 0.7 0.8 0.9 1.0
这道题我想问一下这个doubled 难道不是在上一次的本金+fine上进行doubled 的吗难道只是按第一次的fine 0.1 doubled的吗
然后后面都是这个fine在相加？？？

4 Six countries in a certain region sent a total of 75represetive to an international congress . and no two counteries sent the same numbers of representives of the six countries . if country A sent the second greatest numbers of representives did country A sent at least 10 representives?
(1) One of six counteries sent 41 representives to congress
(2) Country A sent fewer than 12 representives to congress

5 Hery purchase 3 items during a sale he received a 20 present discount off the regular price of the most expensive items and a 10 persent discount off the regular price of each of the other items was the toal amount of the 3 discounts greater than 15 precent of the sum of the regular price of the 3 items ?
(1)The regular price of the most expensive item was $50 and the regular of the next expensive item was $20
(2) the rugular price of the least expensive items was $15
求助这道题的翻译！！

wonderfulwq · 发表于 2010-8-22 12:31:43

楼主你发错地方啦。。。这里是作文区。。。。去数学区发一下八

sara007 · 发表于 2010-8-23 01:39:25

第一道就是说a^2+b^2+c^2=75 求a+b+c 那楼主你就看 75 首先里面有个25可以写成5^2 那接下去就剩个50了。50 里面分一看就知道只有采用49+1这个策略才能写成两个数的平方之和所以a+b+c=5+7+1=13 不过我纯属凑数。。。楼主可以再考虑考虑其他方法！

sara007 · 发表于 2010-8-23 01:46:12

第三道的中文意思是说，图书馆借书超时收罚金，第一天0.1 ，第二天或者是0.1+0.3，或者是0.1*2，哪个小选哪个。那肯定是选0.1*2 咯，选好以后这个就是第二天加上第一天的总罚金数目了，即0.1*2，不用再加上第一天的0.1！

Vickyoo · 发表于 2010-11-7 15:55:04

是0.1,0.2,0.4,0.7 算第四天的时候，是base on第三天的结果0.4，所以0.4+0.3和0.4*2相比选0.7.给以后同学参考吧

Willyum · 发表于 2013-10-27 16:07:28

哦。。。。

马上要考了急！几道prep数学

所属分类: 下线版块

正在浏览此版块的会员 ()

马上要考了 急！几道prep数学

所属分类: 下线版块

正在浏览此版块的会员 ()

马上要考了急！几道prep数学