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If `log_2 x = 6` and `log_3 y = 4` what is `log_12 xy`

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lxsptter | Student, Undergraduate | Valedictorian

Posted May 6, 2013 at 2:54 AM via web

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If `log_2 x = 6` and `log_3 y = 4` what is `log_12 xy`

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justaguide | College Teacher | (Level 2) Distinguished Educator

Posted May 6, 2013 at 3:00 AM (Answer #1)

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It is given that `log_2 x = 6` and `log_3 y = 4` .

`log_2 x = 6` and `log_3 y = 4` 

=> `x = 2^6` and `y = 3^4`

`log_12(x*y)`

= `log_12(2^6*3^4)`

= `log_12 (12^3*3)`

Use the property `log(a*b) = log a + log b`

= `log_12 12^3 + log_12 3`

Use the property `log a^b = b*log a` and `log_b b = 1`

= `3 + log_12 3`

`~~ 3.4421`

The value of `log_12(x*y) = 3 + log_12 3`

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