小三數學, please help ?

(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

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.

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

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

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.

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.