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Đáp án `+` Giải thích các bước giải:

Bài `14:`

`a)5^4=n`

`=>5.5.5.5=n`

`=>625=n`

`=>n=625`

Vậy `n=625`

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`b)n^3=125`

`=>n^3=5.5.5`

`=>n^3=5^3`

`=>n=5`

Vậy `n=5`

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`c)11^n=1331`

`=>11^n=11.11.11`

`=>11^n=11^3`

`=>n=3`

Vậy `n=3`

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Bài `15)`

`a)3.10^3+2.10^2+5.10`

`=` `3.1000+2.100+5.10`

`=` `3000+200+50`

`=` `3205`

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`b)35-2.1^111+3.7.7^2`

`=` `35-2.1+3.7.49`

`=` `35-2+21.49`

`=` `35-2+1029`

`=` `33+1029`

`=` `1062`

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`c)5.4^3+2.3-81.2`

`=` `5.64+2.3-81.2`

`=` `320+6-162`

`=` `326-162`

`=` `164`

$@lingg$