The sum of the present ages of Vatha and Chris is 36. In 4 years time, the
sum of their ages will equal twice Vatha’s present age. How old are they
now?
Maths equations problem
2008-07-27 12:18 am
回答 (4)
2008-07-27 12:29 am
✔ 最佳答案
Let present ages of Vatha is XLet present ages of Chris is Y
SO, X+Y=36............(1)
and, X+4+Y+4=2X....(2)
From (1) get
X=36-Y.......(3)
Sub it into (2)
36-Y+4+Y+4=2(36-Y)
44=72-2Y
-28=-2Y
28=2Y
Y=14
From (3)
X=36-Y=36-14=22
SO,
present ages of Vatha is 22
present ages of Chris is 14
2008-07-27 12:56 am
Let the present age of Vatha be X
,the present age of Chris be Y
then, X + Y = 36 -------(1)
( X + 4 ) + ( Y+ 4 )= 2X----(2)
From , Y + 8 = 2X- X
Y + 8 = X------(3)
SUB ( 3 ) to ( 1 )
then, 2Y + 8 = 36
2Y=28
Y=14
then,by ( 3 ), X = 22
,the present age of Chris be Y
then, X + Y = 36 -------(1)
( X + 4 ) + ( Y+ 4 )= 2X----(2)
From , Y + 8 = 2X- X
Y + 8 = X------(3)
SUB ( 3 ) to ( 1 )
then, 2Y + 8 = 36
2Y=28
Y=14
then,by ( 3 ), X = 22
2008-07-27 12:27 am
Let the present age of Vatha be X
the present age of Chris be Y
then, X + Y = 36 -------(1)
( X + 4 ) + ( Y+ 4 )= 2X----(2)
From , X = Y + 8------(*)
SUB ( * ) to ( 1 )
then, 2Y + 8 = 36
Y=14
then,by ( * ), X = 22
the present age of Chris be Y
then, X + Y = 36 -------(1)
( X + 4 ) + ( Y+ 4 )= 2X----(2)
From , X = Y + 8------(*)
SUB ( * ) to ( 1 )
then, 2Y + 8 = 36
Y=14
then,by ( * ), X = 22
2008-07-27 12:25 am
X=Vatha
y=chris
x+y=36----1
(x+4)+(y+4)=2x-----2
from1,
x=36-y----3
sub 3 into 2,
(36-y+4)+(y+4)=2(36-y)
40-y+y+4=72-2y
2y=28
y=14
sub y=14 into 1
x+14=36
x=22
so that, x=22 y=14
Vatha is 22 Chris is 14 years old!
y=chris
x+y=36----1
(x+4)+(y+4)=2x-----2
from1,
x=36-y----3
sub 3 into 2,
(36-y+4)+(y+4)=2(36-y)
40-y+y+4=72-2y
2y=28
y=14
sub y=14 into 1
x+14=36
x=22
so that, x=22 y=14
Vatha is 22 Chris is 14 years old!
參考: myself
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