[ ( 4X + 28 ) x 3 + 55 ] : 5 = 35
=> ( 4X + 28 ) x 3 + 55 = 175
=> ( 4X + 28 ) x 3 = 120
=> 4X + 28 = 40
=> 4X = 12
=> X = 12 : 4
=> X = 3
[(4x + 28) . 3 + 55] : 5 = 35
=> [(4x + 28) . 3 + 55] = 35 x 5
=> [(4x + 28) . 3 + 55] = 175
=> (4x + 28) . 3 = 175 - 55
=> (4x + 28) . 3 = 120
=> 4x + 28 = 120 : 3
=> 4x + 28 = 40
=> 4x = 40 - 28
=> 4x = 12
=> x = 12 : 4
=> x = 3
mk có trả lời ở bài b đăng trc nhưng sai đề nhé
[ (4x + 28 ) . 3 + 55 ] : 5 = 35
( 4x + 28 ) . 3 + 55 = 35 . 5
( 4x + 28 ) . 3 + 55 = 175
( 4x + 28 ) . 3 = 175 - 55
( 4x + 28 ) . 3 = 120
4x + 28 = 120 : 3
4x + 28 = 40
4x = 40 - 28
4x = 12
x = 12 : 4
x = 3
Vậy x = 3
=))
[(4x + 28) . 3 + 55] : 5 = 35
=> (4x + 28) . 3 + 55 = 175
=>(4x + 28) . 3 = 120
=> 4x + 28 = 40
=> 4x = 12
=> x = 3
~Study well~
#KSJ