Có ai giải giúp em đc k ạ?

`1, `` 3^2 : 3^x = 1`

`<=> 2 : x = 1`

`<=> x = 1 . 2`

`<=> x = 2`

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`2, 5^x : 5^2 = 25`

`<=>5^x : 5^2 = 5^2 `

`<=> 5^x = 5^2 . 5^2 ` 

`<=>  5^x = 5^4`

`<=> x = 4`

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`3, 4^x - 2 = 14`

`<=> 4^x = 14 + 2`

`<=> 4^x = 4^2`

`<=> x = 2`

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`4, 2 . 6^{x-3} =72 `

`<=> 6^{x-3} =72 : 2 `

`<=> 6^{x-3} =36`

`<=> 6^{x-3} =6^2`

`<=> x - 3 = 2`

`<=> x = 2 + 3`

`<=> x = 5`

$\text{#maingoctranthi}$