中一代數式!!10000000000000000萬火急!!!!!!20分

1.2a+7=13
2a=12-7
a=2.5
2.4b–5=–21
4b=-26
b=-6

2007-09-17 22:18:08 補充：
1.2a 7=132a 7-7=13-72a=62a÷2=6÷2a=32.4b–5=–214b-5 5=-21 54b=-16b=-4

2007-09-17 22:18:24 補充：
3.8=18–5c8 5c=18-5c 5c8 5c=188 5c-8=18-85c=105c÷5=10÷5c=24.59–3d=259-3d 3d=2 3d59=2 3d59-2=2 3d-257=3d3d=573d÷3=57÷3d=195.5=9 6–2x5 2x=9 6-2x 2x5 2x=9 65 2x-5=9 6-52x=102x÷2=10÷2x=5

2007-09-17 22:18:50 補充：
6.4 3n–12=254 3n-12 12=25 124 3n=374 3n-4=37-43n=333n÷3=33÷3n=117.11–7y 3=–711–7y 3-3=–7-311-7y=-1011-7y 7y=-10 7y11-(-10)=-10 7y-(-10)21=7y7y=217y÷7=21÷7y=3

2007-09-17 22:19:01 補充：
8.5h 1–4h=105h 1–4h-1=10-15h-4h=9h=99.6m–11m 2=22-5m 2=22-5m 2-(-5m)=22-(-5m)2=22 5m2-22=5m-20=5m5m=-205m÷5=-20÷5m=-410.19–7b–5b=–5319–7b–5b 5b=–53 5b19-7b=53 5b19-7b 7b=53 5b 7b19=-53 12b19-(-53)=-53 12b-(-53)72=12b12b=7212b÷12=72÷12b=6

1
a = 3

2
b = -4

3
2 = c

4
d = 19

5
5 = x

6
n = 11

7
y = 3

8.
h = 9

9.
m = -4

10.
b = 6

1.2a+7=13
2a+7-7=13-7
2a=6
2a÷2=6÷2
a=3
2.4b–5=–21
4b-5+5=-21+5
4b=-16
b=-4
3.8=18–5c
8+5c=18-5c+5c
8+5c=18
8+5c-8=18-8
5c=10
5c÷5=10÷5
c=2
4.59–3d=2
59-3d+3d=2+3d
59=2+3d
59-2=2+3d-2
57=3d
3d=57
3d÷3=57÷3
d=19
5.5=9+6–2x
5+2x=9+6-2x+2x
5+2x=9+6
5+2x-5=9+6-5
2x=10
2x÷2=10÷2
x=5
6.4+3n–12=25
4+3n-12+12=25+12
4+3n=37
4+3n-4=37-4
3n=33
3n÷3=33÷3
n=11
7.11–7y+3=–7
11–7y+3-3=–7-3
11-7y=-10
11-7y+7y=-10+7y
11-(-10)=-10+7y-(-10)
21=7y
7y=21
7y÷7=21÷7
y=3
8.5h+1–4h=10
5h+1–4h-1=10-1
5h-4h=9
h=9
9.6m–11m+2=22
-5m+2=22
-5m+2-(-5m)=22-(-5m)
2=22+5m
2-22=5m
-20=5m
5m=-20
5m÷5=-20÷5
m=-4
10.19–7b–5b=–53
19–7b–5b+5b=–53+5b
19-7b=53+5b
19-7b+7b=53+5b+7b
19=-53+12b
19-(-53)=-53+12b-(-53)
72=12b
12b=72
12b÷12=72÷12
b=6

1)2a+7=13
2a=13-7
a=6

2)4b–5=–21
4b=-21+5
b=-16/4
b=-4

3)8=18–5c10.19–7b–5b=–53
8-18=-5c
-10/-5=c
c=2

4)59–3d=2
-3d=2-59
-3d=-57
d=19

5)5=9+6–2x
9+6-2x=5
2x=5-9-6
x=-10/2
x=-5

6)4+3n–12=25
4+3n=25+12
4+3n=37
3n=37-4
n=33/3
n=11

7)11–7y+3=–7
-7y+3=-7-11
-7y+3=-18
-7y=-21
y=3

8)5h+1–4h=10
5h-4h+1=10
h=10-1
h=9

9)6m–11m+2=22
-5m=20
m=-4

10)19–7b–5b=–53
-7b-5b=-53-19
-12b=-72
b=-72/-12
b=6

2007-09-16 21:04:12 補充：
唔好睇錯d負號bor...希望幫到你啦=]

1) 2a+7=13
2a=13-7
2a=6
a=3

2) 4b-5= -21
4b= -21+5
4b= -16
b= -4

3) 8=18-5c
5c=18-8
5c=10
c=2

4) 59-3d=2
59-2 =3d
57=3d
d=19

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

6) 4+3n–12=25
3n=25-4+12
3n=33
n=11

7) 11–7y+3=–7
11+7+3=7y
21=7y
y=3

8) 5h+1–4h=10
5h-4h=10-1
h=9

9) 6m–11m+2=22
6m-11m=22-2
-5m=20
m= -4

10) 19–7b–5b=–53
19+53=7b+5b
72=12b
b=7

1.2a+7=13
2a=13-7
a=6/2
a=3

2.4b–5=–21
4b=-21+5
b=-16/4
b=-4

3.8=18–5c
-5c=8-18
-5c=-10
c=-10/-5
c=2

4.59–3d=2
-3d=2-59
-3d=-57
d=-57/-3
d=19

5.5=9+6–2x
-2x=5-9-6
-2x=-10
x=-10/-2
x=5

6.4+3n–12=25
3n=25-4+12
3n=33
n=11

7.11–7y+3=–7
-7y=-7-11-3
-7y=-21
y=-21/-7
y=3

8.5h+1–4h=10
5h-4h=10-1
h=9

9.6m–11m+2=22
6m–11m=22-2
-5m=20
m=20/-5
m=-4

10.19–7b–5b=–53
–7b–5b=–53-19
-12b=-72
b=-72/-12
b=6

你自己應該多d計下數,it is so easy to do

1.)2a+7=13
2a=6
a=3
2.)4b-5=-21
4b=26
b=6.5
3.)8=18-5c
-10=-5c
c=2
4.)59-3d=2
-3d=-57
d=19
5.)5=9+6-2x
5=15-2x
-10=2x
x=-5
6.)4+3n-12=25
3n-8=25
3n=33
n=11
7.)11-7y+3=-7
-7y+14=-7
-7y=-21
y=3
8.)5h+1-4h=10
5h-4h=9
h=9
9.)6m-11m+2=22
-5m+2=22
-5m=20
m=-4
10.)19-7b-5b=-23
-12b=-4
b=1/3

1.2a+7=13
2a=13-7
2a=6
a=6/2
a=3
2.4b-5=-21
4b=-21+5
4b=-16
b=-4
3.8=18-5c
8-18=-5c
-10=-5c
c=2
4.59-3d=2
-3d=2-59
-3d=-57
d=19
5.5=9+6-2X
5=15-2X
5-15=-2X
-10=-2X
X=5
6.4+3N-12=25
3N-8=25
3N=33
N=11
7.11-7Y+3=-7
-7Y+14=-7
-7Y=-21
Y=3
8.5H+1-4H=10
1+H=10
H=9
9.6M-11M+2=22
-5m=20
m=-5
10.19-7B-5B=-53
19-12B=-53
-12B=-72
B=6

1.2a+7=13 2a=13-7 2a=6 a=3
2.4b-5=-21 4b=-21+5 4b=-16 4b=-4
3.8=18-5c 18-8=5c 5c=10
4.59-3d=2 -3d=2-59 -3d=-57 d=19
5.5=9+6-2x 2x=9+6-5 2x=10 x=5
6.4+3n-12=25 3n=25-4+12 3n=33 n=11
7.11-7y+3=-7 -7y=-7-11-3 -7y=-21 y=3
8.5h+1-4h=10 5h-4h=10-1 h=9
9.6m-11m+2=22 6m-11m=22-2 -5m=20 m=-4
10.19-7b-5b=-53 -7b-5b=-53-19 -12b=72 b=6
注:有d「-」即係負號，你可能睇唔到，你要認真睇清楚d負號

1. 2a+7=13
2a=13-7
2a=6
a=3

2. 4b-5=21
4b=21+5
4b=26
b=6.5

3. 8=18–5c
-10=-5c
10=5c
c=2

4.59–3d=2
57=3d
d=19

5.5=9+6–2x
5=11-2x
-6=-2x
6=2x
x=3

6.4+3n–12=25
3n=25+12-4
3n=33
n=11

7.11–7y+3=–7
11+3+7=7y
21=7y
y=3

8.5h+1–4h=10
h+1=10
h=9

9.6m–11m+2=22
-5m=20
m=-4

10.19–7b–5b=–53
19-12b=-53
19+53=12b
72=12b
b=6

1)2a+7=13
2a=6
a=3
2)4b-5=-21
4b=-16
b=-4
3)8=18-5c
-10=-5c
c=2
4)59-3d=2
-3d=-57
d =19
5)5=9+6-2x
5=15-2x
-10=-2x
x=5
6)4+3n-12=25
3n=33
n=11
7)11-7y+3=-7
-7y=-7
y=1
8)5h+1-4h=10
5h-4h=9
h=9
9)6m-11m+2=22
-5m+2=22
-5m=20
m=-4
10)19-7b-5b=-53
-7b-5b=-72
-12b=-72
b=6

1. 2A = 13 - 7
2a = 6
a = 3

2. 4B = -21 + 5
4b = -16
b = -4

3. 8 - 18 = -5c
-10 = -5c
2 = c

4. -3d = 2- 59
-3d = -57
d = 19

5. 5 - 9 - 6 = -2x
-10 = -2x
5 = x

6. 3n = 25 - 4 +12
3n = 33
n = 11

7. -7y = -7 - 11 - 3
-7y = -21
y = 3

8. 5h - 4h = 10 - 1
h = 9

9. 6m - 11m = 22 - 2
-5m = 20
m = -4

10. -7b - 5b = -53 - 19
-12b = -72
b = 6

絕對冇錯快比分

1. 2a+7=13
2a=6
a=3

2. 4b-5=-21
4b=-16
b=-4

3. 8=18-5c
8+5c=18
5c=10
c=2

4. 59-3d=2
59=2+3d
57=3d
19=d
d=19

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

6. 4+3n-12=25
3n =33
n=11

7. 11-7y+3= -7
-7y=-21
y=3

8. 5h+1-4h=10
h+1=10
h=9

9. 6m-11m+2=22
-5m +2 =22 (或者可以寫 2-5m=22)
-5m=20 (2=5m+22)
m=-4 (-20=5m)
( -4=m)
( m=-4)

10. 19 -7b-5b=-53
19-12b=-53
19=12b-53
72=12b
6=b
b=6

2007-09-16 20:50:21 補充：
括號純粹係另一種做法,,,其實係可以話冇分別咁濟

2007-09-23 22:46:38 補充：
條友計題數咖bo=口=
唔該帖主比返小小心機去睇....

1) 2a=13-7
2a=6
a=3

2) 4b= -21+5
4b= -16
b= -4

3) 5c=18-8
5c=10
c=2

4) 59-2=3d
57=3d
d=19

5) 5=15 -2x
2x=15-5
2x=10
x=5

6) 3n-8=25
3n=33
n=11

7) 14-7y= -7
21=7y
y=3

8) h=10-1
h=9

9) 2-5m=22
-5m=20
m= -4

10) 19-12b= -53
12b=72
b=6