解方程：求高手教.....有20點

sol

1.
7/10 z-1=5+3/10 z
z(7/10-3/10)=5+1
z(4/10)=6
z=6*10/4=15

2.
x/6+5=x
5=x-x/6
5=5x/6
x=5*6/5=6

3. 1/2=(10-3u)/8
4=10-3u
3u=6
u=2

4. c/4 - (c+3)=6
c-4(c+3)=24
c-4c-12=24
-3c=36
c=12

5. (5d-1)/6+2=(3+d)/6
5d-1+12=3+d
4d=4-12
4d=-8
d=2

6. 2+(2g+1)/3=g/5
15*(2+(2g+1)/3)=g/5*15
30+5(2g+1)=3g
30+10g+5=3g
7g=-35
g=-5

7. (4h-1)/9=(3-h)/6
6(4h-1)=9(3-h)
24h-6=27-9h
33h=33
h=1

8. (2y-1)/6- 1/3 =(5+y)/4
12((2y-1)/6- 1/3)=(5+y)/4*12
2(2y-1)-4=3(5+y)
4y-2-4=15+3y
y=15+6=21

9. x/2 + 5/8 = (x+3)/4
8(x/2 + 5/8)=(x+3)/4*8
4x+5=2(x+3)
4x+5=2x+6
2x=1
x=1/2

2011-10-24 19:16:12 補充：
superbrain ( 小學級 3 級 ):
for example,10 / 3 = 3.3...
I'm just using 'Google 計算機'...

2011-10-24 20:22:21 補充：
for example,in Q1,
lhs=(7/10)*z-1
rhs=5+(3/10)*z
to take (3/10)*z into lhs and take -1 into rhs
iq. (7/10)*z-(3/10)*z=5+1
we see that compare lhs in terms of z ,iq(7/10 - 3/10)z=(4/10)z
known that rhs is 6
take both times (10/4),rhs is 6*10/4=15
when we see that lsh is only z left,then
z=15

頂, 好難睇, 你唔明用除號嫁咩? 定係你係小學生?