方程數學的問題(thx)

1.8=18-5c
5c = 18-8
5c = 10
c = 2

2.59-3d=2
3d = 59-2
3d = 57
d = 19

3.5=9+6-2x
2x = 9 + 6 - 5
2x = 10
x = 5

4.4+3n-12=22
3n = 22 - 4 + 12
3n = 30
n = 10

我e家就係做緊e幾題-3-
新紀元數學 習題2B(p.91)

2008-10-07 15:09:10 補充：
不過有d野提你:
本書第6題即你e道既第4題係 4+3n-12=25
但你寫左4+3n-12=22
不過都唔知你係唔係e本書-3-
提下你啫,冇野la
如果你係用e本既話,e題應該係:
4+3n-12=25
3n=25+12-4
3n=33
n=11

睇你係5係用e本la下~

1. 8=18-5c
18-8=5c
c=5/10
c=2

1. 8=18-5c
8-18=18-5c-18
-10=-5c
-10/5=-5c/5
-2=-c
c=2

2.59-3d=2
59-2=3d
57=3d
57/3=d
19=d

3.5=9+6-2x
2x=9+6-5
2x=10
x=5


4.4+3n-12=22
3n=22+12-4
3n=30
n=10

(1)8=18-5c
5c=18-8
5c=10
c=2

(2)59-3d=2
59-2=3d
57=3d
d=19

(3)5=9+6-2x
2x=9+6-5
2x=10
x=5


(4)4+3n-12=22
3n=22-4+12
3n=30
n=10

1. 1.8=18-5c
解:5c=18-1.8
5c=16.2
c=16.2÷5
c=3.24

2. 59-3d=2
解:3d=59-2
3d=57
d=57÷3
d=19

3. 5=9+6-2x
解:2x=9+6-5
2x=10
x=10÷2
x=5

4. 4+3n-12=22
解:3n=22+12-4
3n=30
n=30÷3
n=10

1. 8=18-5c
5c=18-8
c = 10/2
c=5

2. 59-3d=2
59-2 =3d
57 =3d
d= 19

3. 5=9+6-2x
5=15-2x
2x=15-5
2x=10
x=2

4. 4+3n-12=22
3n-8=22
3n=22+8
3n=30
n=10

8=18-5c
8-18=-5c
-10=-5c
-10 x -1=-1 x -5c
10 = 5c
10/5 = c
c = 2

2008-10-04 09:09:42 補充：
59-3d=2
-3d = 2 - 59
-3d = - 57
d = -57 / -3
d = 19

2008-10-04 09:11:26 補充：
5=9+6-2x
5-9-6 = -2x
-10 = -2x
x = -10/-2
x = 5

2008-10-04 09:15:39 補充：
4+3n-12=22
3n = 22 +12 -4
3n = 30
n= 10