a: =>21x=42

hay x=2

Bài 2: 

a: =>21x=42

hay x=2

x=(9843-123):405=24

  vậy x=24

x= [9843 - 123] ː405= 24 vậy x=24

9843 : x = 405 (dư 123)

=(9843-123):405

=9720:405

=24

a) 5670 : (x × 21) = 135

(x × 21) = 5670 : 135

(x × 21) = 42

x = 42 : 21

x = 2

 5670 : (x × 21) = 135

             x\(\times\)21    = 5670:135

             x × 21   = 42

             x           = 42:21        

             x           = 2

Vậy      x            = 2

x = 2 chúc bạn hc tốt

a: =>21y=105

hay y=5

b: =>50343=405x+123

=>405x=50220

hay x=124

a: =>x*21=3885:37=105

=>x=105:21=5

b: 50343:x=405 dư 123

=>x=(50343-123)/405=124

a, 3885 : (X x 21) = 37
=> 21X = 3885/37
=> 21X = 105
=> X = 5
b, 50343 : X = 405 (dư 123)
=> X = 50343 : 405 + 123
=> X = 33386/135

a) \(3885:\left(x\times21\right)=37\)

\(x\times21=3885:37\)

\(x\times21=105\)

\(x=105:21=5\)

b) \(50343:x=405\)(dư 123)

=> \(405\times x+123=50343\)

\(405\times x=50343-123\)

\(405\times x=50220\)

\(x=50220:405=124\)

a ) 3885 / ( x * 21 ) = 37

x * 21 = 3885 : 37

x * 21 = 105

x  = 105 : 21

x = 5

b ) 50343 : x = 405 ( dư 123 )

x = ( 50343 - 123 ) : 405

x = 50220 : 405

x = 124

c ) 3257 + 25286 : x = 3304

25286 : x = 3304 - 3257

25286 : x = 47

x = 25286 : 47

x = 538

a ) 3885 / ( x * 21 ) = 37

x * 21 = 3885 : 37

x * 21 = 105

x  = 105 : 21

x = 5

b ) 50343 : x = 405 ( dư 123 )

x = ( 50343 - 123 ) : 405

x = 50220 : 405

x = 124

c ) 3257 + 25286 : x = 3304

25286 : x = 3304 - 3257

25286 : x = 47

x = 25286 : 47

x = 538

@_@ k mình nha

x=(50343-123):405
x=50220:405
x=124

x=50343-123) :405

x=50220 :405

x=124

x= 124 nha

HT