方程式 急!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
父年是子年的6倍,父年比子年大25,求父子2人的年歲.
回答 (8)
✔ 最佳答案
設父子分別為 x, y 歲
x = 6y
x = y + 25
6y = y + 25
y = 5
x = 30
Let x be the unknown(father).
6(x-25)=x
6x-150=x
5x=150
x=30
Father:30 Son:5
Another sulution
Bigger one:(Total+Different)/2
Smaller one:(Total-Different)/2
Although we can't use this formula in this equation,remember this.It will be useful!!!
E.g.
Brother and Andy are 28 years old,their different age is 4 years old.Ask their age.
That will be
(28+4)/2=16
(28-4)/2=12 or 16-4(4 is their different)
Understood??
Hope I can help you!!!
2007-06-25 20:06:10 補充:
; ; ;THESE ARE USELESS!!!
子=a
6a=a+25
5a=25
a=5
2007-06-23 18:02:45 補充:
子=5父=30
設兒子的年歲是x。
則父子的年歲是6x。
父 - 子=相差
6x - x= 25
5x=25
x=5
6x=30
所以父親是30歲
兒子是5歲
設子a歲and設父z歲,
6a=a+25
6a-25=a
6a=z
6a-25=z-25
a=z-25
a=z/6
a=5
z=6a
z=30
子5歲and父30歲.
參考: myself
設父是 W & 子是 Y
6Y=W........................................(1)
5Y=25........................................(2)
5Y=25
Y=25/5
Y=5
6Y=W
6(5)=W
30=W
W=30
Let x be the age of father
Let y be the age of son
x=6y -----(1)
x-y=25 -----(2)
Sub (1) into (2)
x-y=25
6y-y=25
5y=25
y=5
The age of son is 5
The age of father = 6x5
=30
參考: me
子=X years old
父=6X years old
6x-x=25
x=5
so:
子=5 years old
父=30 years old
收錄日期: 2021-04-12 19:55:53
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