我唔識le三題數ar?

1) let the large number be x

x+x-8=88

2x=96

x=48

the larger number is 48

2) let her age be y years old

4y-y=27

3y=27

y=9

her age is 9yrs old

3) let the weight of the cake be x g

0.2x+500=1000

0.2x=500

x=2500

the weight of cake is 2500 g

1, 設;較大的數為A,較小的數為B

A=B+8, A+B=88 B=88-A
A=(88-A)+8
A=88-A+8
2A=96
A=96/2
A=48

2,設;翠翠的年齡為A, 父親的年齡為B

A=1/4B, B=A+27
A=1/4(A+27)
A=1/4A+1/4X27
A-1/4A=27/4
3/4A=27/4
A=27/3
A=9

翠翠的年齡是9歲

3, 設蛋糕為A
1/5A+500G=1000G
1/5A=1000G-500G
1/5A=500G
A=500GX5
A=2500G
A=2.5KG

大蛋糕原來的重量是205KG

1)48

2)m......

3)3kg

2006-11-21 22:06:23 補充：
3)not 3kgis...2500g!

1. let be the smallest number is x, the biggest number is x - 8
x + x - 8 = 88
2x - 8 = 80
2x = 80
x = 40
therefore the biggest number is 48
2. let be x is her age.
4y - y = 27
3y = 27
y= 9
therefore her age is 9
3. let be x to ...
1000 = 0.2x + 500
0.2x = 500
x = 2500
therefore the big cake is 2.5kg.

2006-11-27 21:55:10 補充：
4) 4a = ba 4a = 455a = 45a = 9therefore a = 9.

1) (x-8)+x=88

2006-11-21 21:22:07 補充：
(x+27)=1x 4