中二數學題!!!20點入入入

1.
60cm:10m
=60cm:10m*100
=60cm:1000cm
=6:100
=3:50

2.
9:3:12(抽公因數，即係除3)
=(9/3):(3/30):(12/3)
=3:1:4

3.
0.5:1:3.5(乘2令0.5同3.5變整數)
=1:2:7

4.
x:45=4:5
x/45=4/5
x=(4/5)*45
x=32
5.
1200g:3kg =8y :50
1200g/(3kg*1000)=8y/50
1200g/3000g=8y/50
(1200/3000)(50/8)=y
y=2.5
6.
x:(x+6) =4:7
x/(x+6)=4/7
x*7=4(x+6)
7x=4x+24
3x=24
x=8

7.
90 seconds : 1 hour : 40 minutes
90 seconds : 1 hour*60*60 : 40 minutes*60
90 seconds : 3600 seconds : 2400 seconds
3 : 120 : 80

2010-10-04 22:00:28 補充：
第4題答案係36
唔係32

1)60cm:10m
0.6m:10m
6:100
3:50

2)9:3:12
(9/3):(3/3):(12:3)
3:1:4



3)0.5:1:3.5
0.5x2:1x2:3.5x2
1:2:7



4)x:45=4:5
5x=4x45
x=36



6)x:(x+6) =4:7
7x=4(x+6)
=4x+24
3x=24
x=8



7)90:1x60x60:40x60
90:3600:2400
3:120 :80

1)60cm:10m
0.6m:10m
6:100
3:50

2)9:3:12
(9/3):(3/3):(12:3)
3:1:4



3)0.5:1:3.5
0.5x2:1x2:3.5x2
1:2:7



4)x:45=4:5
5x=4x45
x=36



6)x:(x+6) =4:7
7x=4(x+6)
=4x+24
3x=24
x=8



7)90:1x60x60:40x60
90:3600:2400
3:120 :80

1)60cm:10m
0.6m:10m
6:100
3:50

2)9:3:12
(9/3):(3/3):(12:3)
3:1:4



3)0.5:1:3.5
0.5x2:1x2:3.5x2
1:2:7



4)x:45=4:5
5x=4x45
x=36



6)x:(x+6) =4:7
7x=4(x+6)
=4x+24
3x=24
x=8