S.1Maths.(English)

Method 1 ---------- elimination

Let the age of Mr.Chan and his son 's ages be x and y respectively
x + y = 50 ------ (1)
x - y = 32.6 ------ (2)

(1) - (2),
(x + y) - (x - y) = 50 - 32.6
2y = 17.4
y = 8.7

Therefore, Mr.Chan's son is 8.7 years old now.


There is another method to calculate this question


Method 2 ---------- substitution

Let the age of Mr.Chan and his son 's ages be x and y respectively

x + y = 50 ------ (1)
x = 32.6 + y ------ (2)

Sub (2) into (1),

32.6 +y +y = 50
2y = 50-32.6
y = 8.7

Therefore, Mr.Chan's son is 8.7 years old now.



You can ask me if you have any questions~ =]
Hope these can help you~

上面既朋友計錯數．．．．．．
你英文數數，咁我就用英文答你ｌａ～～～

Assume the present ages of Mr.Chanand is 'X' and his son is 'Y'
Then, we get:
X-Y=32..........................(1)
(X+6)+(Y+6)=50..............(2)

From(1), X=32+Y...................(3)

Sub.(3)into(2), we get(32+Y+6)+(Y+6)=50
2Y+44=50
2Y=6
Y=3

Therefore, Mr.Chan's son is 3 years old now.

2008-02-16 15:57:49 補充：
我講緊既係第一位朋友＾＾

2008-02-16 16:02:56 補充：
Remark：Sub. = Substitute = 代.......入ｅ.g.Sub.(3)into(2), 意思姐係　代第(3)條式入去第二條式(2)度p.s.希望幫到你ｌａ～～～

2008-02-16 16:06:34 補充：
仲有一樣野，我諗你個題目ｄ字個位打得唔好，所以有人答左８．７（其實代番入去盲知道錯ｌａ）我諗你果條題目應該係咁：The different between the present ages of Mr.Chanand and his son is 32.6 years later,their total age will be 50 .How old is Mr.Chan's son now?

[(50-6*2)-32]/2
=[(50-12)-32]/2
=(38-32)/2
=6/2
=3

8.7 years old

don't ask me why