中一既數學,,HELP!!(要有式)

1.6C/2(C+5)=80
1.6C = 160 (C+5)
C=100C + 500
C=-500/9

2-0.8C=0.2C-100
2+100 = 0.2C+0.8C
C=102

1.
6(C+5)除2(C+5)=80
6C+30=80(2C+10)
6C+30=160C+800
-770=154C
C=-5

2.
-0.8C=0.2C-100
C=100

1.6c+30=80*(2c+10)

6c+30=160c+800

6c-160c=800-30

-154c=770

c=770*-154

c=-5

2. -0.8c-0.2c=-100

-1c=-100

c=100

2007-01-04 23:52:27 補充：
用錯左*代表除唔好意思所有*都要改用/

Q1
6( C + 5 ) / 2 ( C + 5) = 80
6C + 30 = 80 ( 2C + 10 )
6C + 30 = 160C + 800
- 770 = 154C
C = - 5


Q2
- 0.8C = 0.2C -100
100 = 0.2C + 0.8C
100 = C

2007-01-04 22:08:49 補充：
Q1睇錯左應該係計唔到因為6(C 5)除2(C 5)=80 (c 5)/(c 5)會等於1令到c冇左所以計唔到

1,6(C+5)除2(C+5)=80
6C+30除2C+10=80
6C+30=80乘2C+10
6C+30=160C+800
-800+30=160C-6C
-770=154C
C=-5
2,-0.8C=0.2C-100
-0.8C-0.2C=100
-C=100
C=-100

1. ﹝6(C+5)﹞ /﹝ 2(C+5)﹞ = 80
(6C + 30) /( 2C + 10) = 80
6C + 30 = 80(2C + 10)
6C + 30 = 160C + 800
160C - 6C = 30- 800
154 C = - 770
C = -770 / 154
C = -5

2. -0.8C = 0.2 C -100
-0.8C - 0.2C = -100
-1C = -100
C = -100/-1
C = 100

6(C+5)除2(C+5)=80
6c+30除2c+10=80
3c+3 =80
3c=77
c=77/3


-0.8C=0.2C-100
-0.8C-0.2C= -100
-1C = -100
C= -100

2007-01-04 22:01:12 補充：
C= 100 因為負負得正、 對不住!

1. 6(C+5)/[2(C+5)]=80
6C+30/(2C+10)=80
6C+30=80*(2C+10)
6C+30=160C+800
154C=-770
C=-5

2. -0.8C=0.2C-100
-0.8c-0.2c = -100
-c = -100
c = 100

2007-01-04 22:00:28 補充：
1.6(C 5)除2(C 5)=80

1. 6(C+5)÷2(C+5) = 80
3(C+5) = 80
3C+15 = 80
3C = 65
C = 21 2/3 (21又三份之二)

2. -0.8C = 0.2C-100
-C = -100
C = 100

6(c+5) / 2(c+5)=80
3(c+5)=80
3c+15=80
3c=65
c=65/3

-0.8c=0.2c-100
100=1c
c=100