更新1:
The Ans is 86.
小三數學, please help ?
2010-06-30 2:21 am
Ming and Ling have $282 altogether. If Ling gives Ming $4, Ming would have twice as much money as Ling. How much more money does Ming have than Ling?
回答 (6)
2010-06-30 4:40 am
✔ 最佳答案
(L-4)x2 = (m+4) ... (1)l+m = 282
L = 282-m...(2)
Sub (2) into (1)
(L-4)x2 = (m+4)
(282-m-4)x2 = (m+4)
564-2m -8= m+4
3m = 552
m = 184 ... (3)
Sub (3) into (2)
L = 282-m
L = 282-184
L = 98
M has 184
L has 98
M has (184-98=)86 more than L
2010-06-30 7:18 am
Solve it by Simultaneous Equation.
Let x be the money Ming have,y be the money Ling have.
x+y = 282.............(1)
y-4 = 2(x+4)......................(2)
From (1),
x = 282-y.................(3)
Sub. (3) Into (2),
y-4 = 2[(282-y)+4]
y-4 = 572-2y
y+2y = 572+4
3y = 576
y = 192//
Sub. y = 192 Into (1)
x = 90//
So Therefore,Ming Have $90,Ling Have $192
So Therefore,Ming have more than Ling -102.
Let x be the money Ming have,y be the money Ling have.
x+y = 282.............(1)
y-4 = 2(x+4)......................(2)
From (1),
x = 282-y.................(3)
Sub. (3) Into (2),
y-4 = 2[(282-y)+4]
y-4 = 572-2y
y+2y = 572+4
3y = 576
y = 192//
Sub. y = 192 Into (1)
x = 90//
So Therefore,Ming Have $90,Ling Have $192
So Therefore,Ming have more than Ling -102.
2010-06-30 4:39 am
Ming:x
Ling:y
x+y=282
x =282-y
y-4=2(282-y+4)
y-4=2(286-y)
y-4=572-2y
3y =576
y =192
282-192
=90dollars
Ling:y
x+y=282
x =282-y
y-4=2(282-y+4)
y-4=2(286-y)
y-4=572-2y
3y =576
y =192
282-192
=90dollars
2010-06-30 3:55 am
let Ming money be X , Ling money beY
X+Y=282.......(1)
X+4=2Y-4.........(2)
(1)-(2)
X+Y-X-4=282-2Y-4
Y-4+2Y=282
3Y=282
Y=94
Ling has $94
put Y=94 into(1))
X+94=282
X=188
188-94
=$94
X+Y=282.......(1)
X+4=2Y-4.........(2)
(1)-(2)
X+Y-X-4=282-2Y-4
Y-4+2Y=282
3Y=282
Y=94
Ling has $94
put Y=94 into(1))
X+94=282
X=188
188-94
=$94
2010-06-30 2:50 am
Ming have twice as much money as Ling.This sentence means they all have three times,282/3=94,so Ling have 94 dollars.Ming have 188 dollars.Ling gives Ming 4 dollars,so Ling have 94+4=98 dollars,Ming have 188-4=184 dollars.
2010-06-30 2:47 am
let Ming money be X , Ling money beY
X+Y=282.......(1)
X+4=2Y-4.........(2)
(1)-(2)
X+Y-X-4=282-2Y-4
Y-4+2Y=282
3Y=282
Y=94
Ling has $94
put Y=94 into(1))
X+94=282
X=188
188-94
=$94
2010-06-29 18:49:33 補充：
if the answer is wrong, i say sorry, because this method is not a P.3 student that can used.
X+Y=282.......(1)
X+4=2Y-4.........(2)
(1)-(2)
X+Y-X-4=282-2Y-4
Y-4+2Y=282
3Y=282
Y=94
Ling has $94
put Y=94 into(1))
X+94=282
X=188
188-94
=$94
2010-06-29 18:49:33 補充：
if the answer is wrong, i say sorry, because this method is not a P.3 student that can used.
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原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100629000051KK01175