求助~~~感激不尽!!!泪流满面了先.!!!!

yexianda

he number 75 can be written as the sum of the squares of 3 different positive integers. What is the sum of these 3 integers?   13

Class A, the range of their height is r and greatest g. For class B, the range of their heights is s and the greatest is h. is the least height of the students in class A greater than the least height of the students in class B?C

Three grades of milk are 1 percent, 2 percent, and 3 percent fat by volume. If x gallons of the 1 percent grade, y gallons of the 2 percent grade, and z gallons of the 3 percent grade are mixed to give x+y+z  gallons of a 1.5 percent grade, what is x in terms of y and z? y+3z
没会…

First, it was 4 feet tall, and the height of the tree increased by a constant amount each year for the next 6 years, At the end of the 6th year, the tree was 1/5 taller than it was at the end of the 4th year. By how many feet did the height of the tree increase each year? 2/3
用等差数列为什么做不出来

10.Of the families in City X in 1994, 40 percent owned a personal computer.  The number of families in City X owning a computer in 1998 was 30 percent greater than it was in 1994, and the total number of families in City X was 4 percent greater in 1998 than it was in 1994.  What percent of the families in City X owned a personal computer in 1998?
50%

13.One gram of a certain health food contains 7 percent of the minimum daily requirement of vitamin E and 3 percent of the minimum daily requirement of vitamin A.  If vitamins E and A are to be obtained from no other source, approximately how many grams of the health food must be eaten daily to provide at least the minimum daily requirement of both vitamins?

E33
7.Running at their respective constant rates, machine X takes 2 days longer to produce w widgets than machine Y.  At these rates, if the two machines together produce 5/4 w widgets in 3 days, how many days would it take machine X alone to produce 2w widgets?
12E
这是一道不难得题..为什么硬是没做出来。晕… 我是设Ty=x Tx=x+2 然后5/4w=(w/x+w/x+2)/3 算出x…..