嘉健帶了若干零用錢上街，他先利用一半零用錢買兒童雜誌，然後再用19元購買一個套餐，最後餘下2元。問嘉健原來有多少零用錢呢
回答 (5)
2007-11-17 3:42 am
✔ 最佳答案
設健原來有零用錢n元n/2-19 =2
n/2-19+19=2+19
n/2x2 =21x2
n =42
如果一般
(2+19)x2
=21x2
=42
2007-11-17 8:05 pm
我唔係幾識用中文去寫﹐用英文ok嘛﹖
Let $x be the amount of Ka Kin have
Sol : x/2 - 19 = 2 ← x/2 = 二分之x= x 除二
x/2 = 2+19
x = 21x2
x = 42//
Therefor, Ka Kin have $42 dollars.
Let $x be the amount of Ka Kin have
Sol : x/2 - 19 = 2 ← x/2 = 二分之x= x 除二
x/2 = 2+19
x = 21x2
x = 42//
Therefor, Ka Kin have $42 dollars.
2007-11-17 5:16 am
設原有y元
y/2-19=2
y/2 =2+19
y =21*2
y =42
嘉健原來有42元零用錢
y/2-19=2
y/2 =2+19
y =21*2
y =42
嘉健原來有42元零用錢
收錄日期: 2021-04-13 19:53:12
原文連結 [永久失效]:
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