小二上學期數學急問(請提供算式及答案)
甲和乙各有一些貼紙.
若甲給乙5張, 則甲和乙的貼紙數量相同;
若乙給甲5張, 則甲是乙的3倍.
甲原來有___張貼紙.
小二上學期數學急問
2011-05-09 4:40 am
回答 (3)
2011-05-10 7:20 am
✔ 最佳答案
Let 甲 be a and let 乙 be b, a-5 =b+5 - (1)
3(b-5) = a+5 - (2)
(1)-(2)
-10 = b+5 -3b+15
-10 = -2b + 20
2b = 10+20
b (i.e.乙 )=15
Sub. b = 15 into (1),
a (i.e.甲) =25
P.S. 甲有二十五張, 給乙五張 ----> 甲現在有二十張, 乙就有 (15+5) 二十張.
乙給甲5張 , 即乙有十張 ---> 甲有 (25 +5) 三十張 (乙的3倍)
by Jeffrey
http://cytc-jeffrey.blogspot.com/
2011-05-10 1:59 am
Acct : Your answer is wrong !
2011-05-09 5:14 am
(1) 甲-5=乙
(2) 甲+5=3乙
(2) - (1)
2乙 = 10
乙 = 5
甲 = 10
(2) 甲+5=3乙
(2) - (1)
2乙 = 10
乙 = 5
甲 = 10
收錄日期: 2021-04-13 17:59:06
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20110508000051KK01279