iq 共有多少人出席該晚活動
回答 (3)
2006-12-04 1:32 am
✔ 最佳答案
計埋浩賢,一共有8個人出席因為280/8=35(元)
280/(8-1)= 40元
35元+5元 = 20元
2006-12-17 4:27 am
假設有x個人(不計浩賢),每人付$y.
y(x+1)=280 ---(1)
y= 5x --- (2)
sub. (2) into (1)
5x(x+1)=280
x(x+1) = 56
x^2 + x - 56 = 0
(x+8)(x-7)=0
x=7 or x=-8 (rejected)
所以一共有7+1 = 8個人
y(x+1)=280 ---(1)
y= 5x --- (2)
sub. (2) into (1)
5x(x+1)=280
x(x+1) = 56
x^2 + x - 56 = 0
(x+8)(x-7)=0
x=7 or x=-8 (rejected)
所以一共有7+1 = 8個人
2006-12-04 2:40 am
let x be 出席該晚活動的人數 , y be 每人應付款項 :
xy=280.............................(1)
(x-1)(y+5)=280...................(2)
from (1),
xy=280
y=280/x.....................(3)
put (3) into (2)
(x-1)(280/x+5)=280
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xy=280.............................(1)
(x-1)(y+5)=280...................(2)
from (1),
xy=280
y=280/x.....................(3)
put (3) into (2)
(x-1)(280/x+5)=280
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收錄日期: 2021-04-12 22:32:43
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