2^3 .4^2 +3^2 .3^2 -40 3.{29-[2021^0 +2.(2. 3^2 - 9^3 :9^2 )]} (19x + 13^2):5=49 74+2^x-2 =106 ^ ^ mong ai đó giúp

Đáp án:

`2^3 .4^2 +3^2 .3^2 -40`

`= 8 . 16 + 81 - 40`

`= 169`

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`3.{29-[2021^0 +2.(2. 3^2 - 9^3 :9^2 )]}`

`= 3 . {29 - [1  + 2 . ( 2 . 9 - 9 )]}`

`= 3. {29 - [ 1 + 2 . 9 ]}`

`= 3 . (29 - 19 )`

`= 3 . 10 `

`= 30`

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`(19x + 13^2):5=49`

`(19x + 169 ) = 245`

`19x = 76`

`x=76:19`

`x = 4`

Vậy `x = 4`

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`74+2^(x-2) =106`

`2^(x-2) = 32`

`2^(x-2) = 2^5`

`x - 2 = 5`

`x=5+2`

`x = 7`

Vậy `x = 7`

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Giải thích các bước giải:

`2^3 .4^2 +3^2 .3^2 -40`

`= 8 . 16 + 81 - 40`

`= 128 + 81 - 40`

`= 169`

`3.{29-[2021^0 +2.(2. 3^2 - 9^3 :9^2 )]}`

`= 3 . {29 - [1  + 2 . ( 2 . 9 - 9 )]}`

`= 3. {29 - [ 1 + 2 . 9 ]}`

`= 3 . (29 - 19 )`

`= 3 . 10 = 30`

`(19x + 13^2):5=49`

`(19x + 169 ) = 245`

`19x = 76`

`x = 4`

Vậy `x = 4`

`74+2^(x-2) =106`

`2^(x-2) = 32`

`2^(x-2) = 2^5`

`x - 2 = 5`

`x = 7`

Vậy `x = 7`