[(4x + 28) . 3 + 55] : 5 = 35 (12x - 4^3) . 8^3 = 4 . 8^4 720 : [41- (2x - 5)] 2^3 . 5

`[ ( 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`

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`(12x - 4^3).8^3 = 4.8^4`

`(12x - 64).512 = 16384`

`12x - 64 = 16384 : 512`

`12x - 64 = 32`

`12x = 32 + 64`

`12x = 96`

`x = 96 : 12`

`x=8`

Vậy `x=8`

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`720:[41-(2x-5)]=2^3 .5`

`720:[41-(2x-5)]=40`

`41-(2x-5) =720:40`

`41-(2x-5) =18`

`2x-5 =41-18`

`2x-5 =23`

`2x =23+5`

`2x =28`

`x =28:2`

`x =14`

Vậy `x=14`