close
Blogtrottr
Yahoo!奇摩知識+ - 分類問答 - 科學常識 - 投票中
Yahoo!奇摩知識+ - 分類問答 - 科學常識 - 投票中 
Get the newest, latest, hottest

Find shoes, heels, flats, active, essentials and more in the latest styles. Save up to 40% on select items.
From our sponsors
一題方程式題目
Sep 22nd 2013, 13:19

設瓶蓋容量為x單位，整瓶是y單位

所以誤看而使用的5n次中，共用去了5n．x/2 = 5nx/2

此時發現用錯了，而剩下的是(n-1)/n，也就是用去了1/n
所以用去的 5nx/2 : y = 1 : n

=>y = 5xn^2/2
=>2y = 5xn^2

此時剩下 y - 5nx/2，還可以用21n+6次，(這時改回來用正確的用量，每次x/3)
表示 (y - 5nx/2) ÷ x/3 = 21n+6

=> y - 5nx/2 = (21n+6)．x/3 = 7nx + 2x
=> 2y - 5nx = 14nx + 4x
 
2y = 5xn^2代入上式
=>
5xn^2 - 5nx = 14nx + 4x
=>
5xn^2 - 19nx - 4x = 0
5n^2 - 19n - 4 = 0
(5n + 1)(n - 4) = 0
n = 4 (負不合)
 
因為2y = 5xn^2
=>y/x = 5n^2/2 = 5．4^2/2 = 5．16/2 = 40

 

This entry passed through the Full-Text RSS service — if this is your content and you're reading it on someone else's site, please read the FAQ at fivefilters.org/content-only/faq.php#publishers. Five Filters recommends:

You are receiving this email because you subscribed to this feed at blogtrottr.com.

If you no longer wish to receive these emails, you can unsubscribe from this feed, or manage all your subscriptions
arrow
arrow
    全站熱搜
    創作者介紹
    創作者 koassq 的頭像
    koassq

    線上遊戲排行榜2013/2014,進擊的巨人線上看,candy crush saga外掛,正妹寫真三圍

    koassq 發表在 痞客邦 留言(0) 人氣()

    E-mail轉寄