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kandsbbf Group Title

Find the real solutions of the equation by graphing. –8x3 – 17x2 + 7x = 0

  • one year ago
  • one year ago

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  1. kandsbbf Group Title
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    @zepdrix

    • one year ago
  2. kandsbbf Group Title
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    0, –2.48, 0.35 –2.48 –2.48, 0.35 0, 2.48, –0.35

    • one year ago
  3. kandsbbf Group Title
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    @zepdrix

    • one year ago
  4. zepdrix Group Title
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    lol once is enough ^^ sorry I'm also helping someone else so it's hard to get away XD

    • one year ago
  5. kandsbbf Group Title
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    i didn't mean too lol my cp is slow.. thought u didn't get it

    • one year ago
  6. zepdrix Group Title
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    \[\large -8x^3-17x^2+7x=0\]See how EVERY term has an X in it? Let's start by factoring an X out of each term.\[\large x(-8x^2-17x+7)=0\]

    • one year ago
  7. zepdrix Group Title
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    I know they said to solve by GRAPHING, but I'm not exactly sure how you would go about doing that. Do they mean by using a calculator?

    • one year ago
  8. zepdrix Group Title
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    Graphing Calculator*?

    • one year ago
  9. zepdrix Group Title
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    Anyway doing it this way, if we apply the Zero Factor Property, we'll set each factor equal to 0 giving us,\[\large x=0 \qquad \text{and}\qquad -8x^2-17x+7=0\]

    • one year ago
  10. kandsbbf Group Title
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    maybe but i don't have one and their are actual graphs as the answersbut i just gave u the points.....

    • one year ago
  11. kandsbbf Group Title
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    okayy

    • one year ago
  12. zepdrix Group Title
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    From here, we can immediately cancel out two of the options, because it has to be one of the choices with x=0.

    • one year ago
  13. zepdrix Group Title
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    To find the other two roots, we can throw the quadratic part into the Quadratic Formula.\[\large ax^2+bx+c=0 \qquad \rightarrow \qquad x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}\]

    • one year ago
  14. zepdrix Group Title
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    \[\large -8x^2-17x+7=0 \qquad \rightarrow \qquad x=\frac{17 \pm \sqrt{17^2-4(-8)(7)}}{2(-8)}\]

    • one year ago
  15. zepdrix Group Title
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    Hopefully I plugged that in correctly. You can punch that into your calculator and hopefully get something that's listed :O

    • one year ago
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