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Math quesion, please help me!?

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the problem is 2x^7/2+8x^5/2=24x^3/2 the directions says solve by factoring and the hint for the problem is "first factor out a fractional root" i am not sure how to do that so please can someone help me!

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  1. solution...

    2x^7/2 + 8x^5/2 - 24x^3/2 = 0....transfer the 24x^3/2 to the left.

    2(x^7/2 + 4x^5/2 - 12x^3/2) = 0...factor the common between the three values which is 2...

    2(x^7 + 4x^5 - 12x^3)^1/2 = 0...the factor inside the parenthesis is 1/2...


  2. (1) I assume your expression (more) accurately reads:

    2x^(7/2) + 8x^(5/2) = 24x^(3/2)

    (2) If so, a factor common to all three terms is:

    x^(3/2),

    so factoring that out and equating the expression to zero gives:

    x^(3/2)*[2x^2 + 8x - 24] = 0

    (3) One of the solutions is x = 0

    (4) The other (non-zero) solutions are obtained as follows:

    (5) Divide by x^(3/2) and 2, obtaining

    x^2 + 4x - 12 = 0,

    which is factored to read: (x + 6)(x - 2) = 0

    (6) Hence, the solutions are: x = 0, x = - 6 and x = + 2.

  3. 2x^7/2+8x^5/2=24x^3/2

    2x^7/2 + 8x^5/2 - 24x^3/2 = 0

    What the hint is saying is that square root of x is in all 3 terms and can be factored out.

    √x (2x^7 + 8x^5 - 24x^3) = 0

    2x³ can also be factored out

    x³√x (x^4 + 4x^2 - 12) = 0

    now you can factor

    x³√x (x² + 6)(x² -  2) = 0

    x³√x (x² + 6)(x + 2)(x - 2) = 0

    solutions are x = 0, +2, -2, +6i, -6i

    .


  4. 2x^7/2 + 8x^5/2 = 24x^3/2

    2x^4 * x^(3/2) + 8x^2 * x^(3/2) = 24 * x^(3/2)

    2x^4 * x^(3/2) + 8x^2 * x^(3/2) - 24 * x^(3/2) = 0

    x^(3/2) (2x^4 + 8x^2 - 24) = 0

    x^(3/2) (2x^2 + 12)(x^2 - 2) = 0

  5. Subtract 24x^3/2 from both sides, then factor out what they have in common : 2 x^(3/2)

    2x^(3/2) [ x^ (4/2) + 4x ^ (2/2) - 12 ] = 0 which simplifies to

    2x ^ (3/2) [ x^2 + 4x - 12 ] = 0

    (2x^(3/2)) (x + 6) (x - 2) = 0....use zero product property

    2x^(3/2) = 0 OR x + 6 = 0 OR x - 2 = 0

    Solve each equation for x

    x = 0 or x = - 6 or x = 2

    This was a tough problem !

    Good luck to you !  

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