F.1 maths

1) 4 x - 2x / 5 = 1
(4 x - 2x / 5 )x5 = 5
20x - 2 x = 5
18 x = 5
x = 5/ 18
3) n/ 4 = 5n / 8 +3
( n/ 4 )x 8 = (5n / 8 +3 ) x 8
2n = 5n + 24
- 24 = 3 n
n = -8
5) m / 2 - 3 m = 5
(m / 2 - 3 m ) x 2 = 5 x 2
m - 6 m = 10
-5 m = 10
m = -2
7) x - (4x-2)/8 = -x / 4
[x - (4x-2)/8 ] x 8 = (-x / 4) x 8
8 x - (4x - 2) = -2x
8 x - 4x + 2 = -2x
6 x = -2
x = - 1/3
9) 6/5 x (n-2) +4 = -8
[6/5 x (n-2) +4 ] x 5 = -8 x 5
6 (n-2) + 20 = -40
6 (n-2) = - 60
n - 2 = -10
n = - 8



2006-11-12 00:06:04 補充：
Netfriend " yeungchiyik " 's answer in Question 3 is wrong in the 2nd step :8(n/4)=8(5n/8+3) 2n=5n+3 (X)2 n = 5n + 24 (Correct)Just a careless mistake ^^

你的方程式是(大約)

1.4x-2x/5=1

3.n/4=5n/8+3

5.m/2-3m=5

7.x-4x-2/8= -x/4

9.6/5*(n-2)+4= -8

答案：

1.x=5/18 18係分母 5係分子

3.n= -8

5.m= -2

7.x= -1/3 1係分母 3係分子

9.n= -8

因無法詳細打進方程式(會混淆和不清楚)
所以沒有步驟
不便之處
敬請原諒!

4x-2x/5=1
5(4x-2x/5)=5
20x-2x=5
18x=5
x=5/18

n/4=5n/8+3
8(n/4)=8(5n/8+3)
2n=5n+3
3n= -3
n= -1

m/2-3m=5
2(m/2-3m)=10
m-6m=10
-5m=10
m=-2

x-(4x-2)/8= -x/4
8(x-(4x-2)/8)=8(-x/4)
8x-(4x-2)=-2x
8x-4x+2=-2x
6x=-2
x=-1/3

6/5(x)(n-2)+4= -8
兩個未知數,做不到

2006-11-11 23:47:27 補充：
可以化簡一點吧/....6/5(x)(n-2)+4= -8x(n-2)= -10nx-2x+10=0

唔係好明=.="
load唔到?