方程式 急!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

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.

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

子=X years old
父=6X years old
6x-x=25
x=5

so:
子=5 years old
父=30 years old