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If 4^(3x^2 - 18) = 8 what is x.

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xetabeta | Student, Kindergarten | (Level 1) Salutatorian

Posted September 10, 2013 at 6:12 AM via web

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If 4^(3x^2 - 18) = 8 what is x.

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justaguide | College Teacher | (Level 2) Distinguished Educator

Posted September 10, 2013 at 6:16 AM (Answer #1)

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The equation `4^(3x^2 - 18) = 8` has to be solved for x.

`4^(3x^2 - 18) = 8`

=> `2^(2*(3x^2 - 18)) = 2^3`

=> `2^(6x^2 - 36) = 2^3`

Equate the exponent and solve for x.

`6x^2 - 36 = 3`

=> `6x^2 - 39 = 0`

=> `x^2 = 13/2`

=> `x = +- sqrt(13/2)`

The solution of the equation is `x = +- sqrt(13/2)`

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