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`3x^2-x=56`  solve for x

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valseds | Student, Grade 10 | (Level 1) eNoter

Posted May 18, 2012 at 3:02 AM via web

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`3x^2-x=56`  solve for x

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utilityfan | Student, College Freshman | (Level 1) Valedictorian

Posted May 18, 2012 at 3:14 AM (Answer #1)

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3x^2-x=56

3x^2-x-56=0

Use the quadratic formula to get: -4.14 and 4.4 as your roots.

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hala718 | High School Teacher | (Level 1) Educator Emeritus

Posted May 18, 2012 at 3:16 AM (Answer #2)

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Given the equation:

`3x^2 - x = 56`

==> `3x^2 -x -56= 0`

We have a quadratic equation which we can use by factoring or using the quadratic formula.

==> `x= (-b+-sqrt(b^2-4ac))/(2a)`

==> `x1= (1+sqrt(1+4*3*56))/(2*3)`

==> `x1= (1+sqrt(672))/6 = (1+4sqrt42)/6` 

==> `x2= (1-4sqrt42)/6`

Then, we have two roots.

`==> x' = { (1+4sqrt42)/6 , (1-4sqrt42)/6 }`

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just-s | Student, Grade 11 | (Level 1) Valedictorian

Posted May 18, 2012 at 12:54 PM (Answer #3)

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3x^2-x=56

3x^2-x-56=0

now you must use the quadratic formulae and get: -4.14 / 4.4 as your roots.^_^

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