五條數二十分

x+6 = 2(x+5)
x+6 = 2x + 10
x-2x = 10-6
-x = 4
x = -4
4(3-x)-5(6-x) = 0
12-4x-30+5x = 0
x-18 = 0
x = 18
2(x+3)+3(x-1)=18
2x+6+3x-3 = 18
5x+3 =18
5x = 15
x = 3
2[x-2(2-3x)]=13x+4
2(x-4+6x) = 13x+4
2x-8+12x = 13x+4
14x-13x = 4+8
x = 12
5[2(x-3.2)+x] = x-4
5(2x-6.4+x = x-4
10x-11.4+5x = x-4
15x-x = -4+11.4
14x = 7.4
x = 14分之7.4
包保全部都一定啱，唔啱就檢舉我，上面果個計錯數，應該先計細括 ( )，然後先中括 [ ]


2007-11-21 20:36:26 補充：
第５題漏左閂括，唔好意思5[2(x-3.2) x] = x-45(2x-6.4) x = x-410x-11.4 5x = x-415x-x = -4 11.414x = 7.4x = 14分之7.4

2007-11-25 11:11:14 補充：
我都唔知你叫咩名

1.x+6 = 2(x+5)

x+6 = 2x + 10

x-2x = 10-6

-x = 4

So, x = -4

2.4(3-x)-5(6-x) = 0

12-4x-30+5x = 0

x-18 = 0

So, x = 18

3.2(x+3)+3(x-1)=18

2x+6+3x-3 = 18

5x+3 =18

5x = 15

x = 3

4.2[x-2(2-3x)]=13x+4

2[x-4+6x]=13x+4

2x-8+12x=13x+4

-8-4=13x-12x-2x

-12=-x

So, x=12

5. 5[2(x-3.2)+x]=x-4

5[2x-6.4+x]=x-4

10x-32+5x=x-4

5x-32=x-4

5x-x=-4+32

4x=28

So, x=7

1. x+6=2(x+5)
6=2x+10-x
x=-4

2. 4(3-x)-5(6-x)=0
12-4x-30+5x=0
x=18

3. 2(x+3)+3(x-1)=18
2x+6+3x-3=18
5x=15
x=3

4. 2[x-(2-3x)]=13x+4
2x-4+6x=13x+4
-8=5x
x=-8/5

5. 5[2(x-3.2)+x]=x-4
5(2x-6.4+x)=x-4
10x-12.8+5x=x-4
14x=8.8
x=22/15

2007-11-22 07:55:21 補充：
5. 5[2(x-3.2) x]=x-4 5(2x-6.4 x)=x-410x-32 5x=x-414x=28x=14

2007-11-22 07:58:13 補充：
2[x-2(2-3x)]=13x 44. 2[x-(2-3x)]=13x 4樓下第４條看題目

2007-11-24 15:00:20 補充：
5 x=2