哈哈爸 2009-5-2 09:46
再求助
2. How many whole numbers from 1 to 1000 can be expressed as the difference of the squares of two whole numbers? [ Note : 0 is a whole number.]
[Omission of essential working will result in loss of marks].
greenjyz 2009-5-3 22:00
回复 1#哈哈爸 的帖子
1000.
n^2-m^2 = (n-m)(n+m)
Let n-m=1, n+m=1,3,5,7,....
Let n-m=2, n+m=2,4,6,8,......
哈哈爸 2009-5-3 22:30
回复 2#greenjyz 的帖子
多次得到您的帮助,谢谢greenjyz ..