Question

Tìm x trong các tỉ lệ thức sau:

a, 3,8 : ( 2x ) = 1/4 : 8/3

b, ( 0,25x ) : 3 = 5/6 : 0,125

c, 0,01 : 2,5 = ( 0,75x ) : 0,75

d, 4/3 : 0,8 = 2/3 : ( 0,1x )

Answer 1

( 0,25x ) : 3 = 5/6 : 0,125

( 1/4x ) : 3 = 5/6 : 1/8

( 1/4x ) : 3 = 5/6 x 8

( 1/4x ) : 3 = 20/3

1/4x          = 20/3 x 3

1/4x         = 20

x              = 20 : 1/4

x              = 80

 

Answer 2

0,01 : 2,5 = ( 0,75x ) : 0,75

1/100 : 25/10 = (3/4x) : 3/4

1/100 x 10/25 = (3/4x) : 3/4

=>(3/4x) : 3/4 = 1/250

3/4x                = 1/250 x 3/4

3/4x                = 3/1000

x                     = 3/1000 : 3/4

x                     = 1/250

 

 

Answer 3

 4/3 : 0,8 = 2/3 : ( 0,1x )

<=>2/3 : (0,1x) = 4/3 : 0,8

2/3 : (0,1x) = 4/3 : 4/5

2/3 : (0,1x) = 4/3 x 5/4

2/3 : (0,1x) = 5/3

2/3 : (1/10x) = 5/3

1/10x           = 2/3 : 5/3

1/10x           = 2/3 x 3/5

1/10x           = 2/5

x                  = 2/5 : 1/10

x                  = 2/5 x 10

x                  = 4

 

Answer 4

 

a, 3,8 : ( 2x ) = 1/4 : 8/3

= 38/10 : ( 2x) = 1/4 x 3/8

= 38/10 : (2x)  = 3/32

                2x     =  38/10 : 3/32

                2x      = 38/10 x 32/2

                2 x     = 304/5

                 x        = 304/5 : 2

                 x        = 304/5 x 1/2

                 x         = 152/5