[124-(20-4x)] :30+7=11

2 câu trả lời

`[124 - (20- 4x)] : 30 + 7 = 11`

`=> [124 - (20- 4x)] : 30 = 11 - 7`

`=> [124 - (20 - 4x)] : 30 = 4`

`=> 124 - (20 - 4x) = 4 . 30`

`=> 124 - (20 - 4x) = 120`

`=> 20 - 4x = 124 - 120`

`=> 20 - 4x = 4`

`=> 4x = 20 - 4`

`=> 4x = 16`

`=> x = 16 : 4`

`=> x = 4`

Vậy `x = 4`

`#dtkc`

`[ 124 - ( 20 - 4x ) ] : 30 + 7 = 11`

`=> [ 124 - ( 20 - 4x ) ] : 30 = 11 - 7`

`=> [ 124 - ( 20 - 4x ) ] : 30 = 4`

`=> 124 - ( 20 - 4x ) = 4. 30`

`=> 124 - ( 20 - 4x ) = 120`

`=> 20 - 4x = 124 - 120`

`=> 20 - 4x = 4`

`=> 4x = 20 - 4`

`=> 4x = 16`

`=> x = 16 : 4`

`=> x = 4`

 $Vậy$ `x = 4`