小六升中1數學(急急急,快快快)

1/5=2x-1/21
5(2x-1)=21
10x-5=21
10x=26
x=2.6 or 13/5 or 2又3/5

普通一般

1/5 = (2x-1)/21
105 (1/5) = 105 [(2x-1)/21]
21 = 5 (2x-1)
21/5 = 2x-1
26/5 = 2x
x = 26/10 (2.6)

21分之2x-1=5分之1
21分之2x=5分之1+1
21分之2x=5分之6
x=5分之6乘2分之21
x=5分之3乘1分之21
x=5分之63
x=12又5分之3

2x-1/21=1/5
2x=1/5+1/21
2x=21/105+5/105
x=26/105除2
x=13/105

我估你的算式是1/5=(2x-1)/21
* 代表乘號 / 代表除號
1/5 = (2x - 1)/21
21*1 = 5*(2x - 1)
21 =10x - 5
10x = 21 + 5
x = 26/10
x = 13/5 or x = 2.6

1/5=2x-1/21
21/105=2x-5/105
26/105=2x
2x=26/105
x=26/105x1/2
x=13/105

希望幫到你啦！！

1 / 5 = ( 2x - 1 ) / 21
1 / 5 * 21 * 5 = ( 2x - 1 ) / 21 * 21 * 5
21 = 5 ( 2x - 1 )
21 = 10x - 5
10x = 26
x = 26/ 10 = 2.6 = 2又3/5

2007-08-03 16:11:31 補充：
x = 26/ 10 = 13/5 = 2.6 = 2又3/5

1/5=(2x-1)/21
21=10x-5
26=10x
x=13/5

i hope that i can help u

1/5+1/21=2x
26/105=2x
26/106 / 2 =x
x=13/105