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Given that 3^(3x+2)  *  7^(x-1)=81^x * 7^2x Find the value of 21^x

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inquire123 | Student | eNoter

Posted April 1, 2013 at 12:50 PM via web

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Given that 3^(3x+2)  *  7^(x-1)=81^x * 7^2x

Find the value of 21^x

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pramodpandey | College Teacher | Valedictorian

Posted April 1, 2013 at 1:28 PM (Answer #1)

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`3^(3x+2)xx7^(x-1)=81^x xx 7^(2x)`

`3^((3x+2)}xx7^(x-1)=(3^4)^(x) xx7^(2x)`

`` `3^(3x+2)xx7^(x-1)=3^(4x)xx7^(2x)`

`{3^(3x+2)xx7^(x-1)}/{3^(4x)xx7^(2x)}=1`

`3^(3x+2-4x)xx7(x-1-2x)=1`

`3^(2-x)xx7(-1-x)=1`

`{3^2xx7^(-1)}/{3^(x)7^(x)}=1`

`9xx7^(-1)=(3xx7)^x`

`(21)^x=9/7`

 

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