數學題(方程式)唔識計唔該呀
回答 (7)
2007-06-01 6:23 am
✔ 最佳答案
Y + 16 = 2 x (Y-12)Y + 16 = 2Y - 24
Y = 40
2007-06-02 4:58 am
1.某人16年後的年歲是他12年前的年齡的2倍,要計佢現在年齡
設某人現在a歲。
a+16=2(a-12)
a+16=2a-24
a =2a-24+16
a =2a-30
2a-a=30
a =30
設某人現在a歲。
a+16=2(a-12)
a+16=2a-24
a =2a-24+16
a =2a-30
2a-a=30
a =30
2007-06-01 6:56 am
let 某人e+年齡 is a歲
a+16=(a-12)*2
a+16=2a-24
a=2a-40
2a-a=40
a=40
某人e+年齡=40歲
a+16=(a-12)*2
a+16=2a-24
a=2a-40
2a-a=40
a=40
某人e+年齡=40歲
2007-06-01 6:40 am
設他是e歲 ｏ
12÷2=e-12
12÷2×2=e-12×2
12÷2=e-12×2÷2
6+12=e-12+12
18=e
∴他是18歲ｏ
我有信心,一定yes
2007-05-31 22:43:42 補充：
我錯咗設他是x歲 ｏx+16=(x-12)*2x+16=2x-24x=2x-4040=2x-x40=x∴他是40歲ｏ
12÷2=e-12
12÷2×2=e-12×2
12÷2=e-12×2÷2
6+12=e-12+12
18=e
∴他是18歲ｏ
我有信心,一定yes
2007-05-31 22:43:42 補充：
我錯咗設他是x歲 ｏx+16=(x-12)*2x+16=2x-24x=2x-4040=2x-x40=x∴他是40歲ｏ
參考: me
2007-06-01 6:37 am
Let x years old be the age of him/her.
x + 16 = 2(x-12)
x + 16 = 2x - 24
x - 2x = - 16 - 24
x = 40
So he is 40 years old now.
x + 16 = 2(x-12)
x + 16 = 2x - 24
x - 2x = - 16 - 24
x = 40
So he is 40 years old now.
參考: myself
2007-06-01 6:31 am
let x be the e+年齡of某人
x+16=(x-12)*2
x+16=2x-24
x=2x-40
40=2x-x
40=x
so 某人e+年齡=40
x+16=(x-12)*2
x+16=2x-24
x=2x-40
40=2x-x
40=x
so 某人e+年齡=40
2007-06-01 6:26 am
X +16 = 2*(X-12)
X + 16 = 2X-24
2X-24-X-16=0
X-40=0
X=40
X + 16 = 2X-24
2X-24-X-16=0
X-40=0
X=40
收錄日期: 2021-04-23 21:48:00
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070531000051KK04540