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Math Help - Quadratic Equation

  1. #1
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    Quadratic Equation

    Solve

    -16x^(-2)+2x=0

    answer=2 or 0

    and

    -9x^2+1=0


    but how do you do it?

    million thanks!
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  2. #2
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    Hello, BabyMilo!

    Solve: . -16x^{-2}+2x\:=\:0

    Answer: 2\text{ or }0 . . . . not true

    but how do you do it?

    We have: . 2x - 16x^{-2} \:=\:0

    Multiply by x^2\!:\;\;2x^3 - 16 \:=\:0

    Factor: . 2(x^3-8)\:=\:0 \quad\Rightarrow\quad x^3 \:=\:8

    Therefore: . x \:=\:2

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  3. #3
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    thanks!
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  4. #4
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    Quote Originally Posted by BabyMilo View Post

    -9x^2+1=0


    but how do you do it?

    million thanks!
    -9x^2 + 1 = 0
    -9x^2 = -1
    x^2 = 1/9
    x = 1/3
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