操作——这两个操作的结果是否相似?

Operations - Are the results of these two operations similar to each other?

给定两组数字,即

[3, 4, 5][7, 8, 9]

(3/7 + 4/8 + 5/9)3 * (3 + 4 + 5) / (7 + 8 + 9) 的结果是否相似?这有任何定理吗?

让我们把反转的问题:

Can difference between a / d + b / e + c / f and 3 * (a + b + c) / (d + e + f) be arbitrary large?

答案是肯定:

a = c = d = e = 1b = f是一个大数。我们有:

a / d + b / e + c / f = 1 / 1 + b / 1 + 1 / b ~ b + 1
3 * (1 + b + 1) / (1 + 1 + b) = 3

区别是

b + 1 - 3 = b - 2

f = b任意大时,差值(b - 2)也是任意大

这就是为什么 原始问题 的答案是

there's no guarantee that the results will be similar, i.e. close enough