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anonymous

  • 4 years ago

How do I get from 2a+a+sqrt(3a^2)=20 to.... a=8.453?

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  1. anonymous
    • 4 years ago
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    How did you arrive at that answer?

  2. anonymous
    • 4 years ago
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    wolframalpha.com

  3. anonymous
    • 4 years ago
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    are you sure you plugged it in correctly?

  4. anonymous
    • 4 years ago
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    I entered the equation exactly how it here.

  5. anonymous
    • 4 years ago
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    Then you must've typed it here wrong. That is not the correct answer.

  6. anonymous
    • 4 years ago
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    Double check

  7. anonymous
    • 4 years ago
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    http://www.wolframalpha.com/input/?i=2a%2Ba%2B+sqrt%283a%5E2%29%3D20 are you able to see this, my friend?

  8. anonymous
    • 4 years ago
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    \[2a+a+\sqrt(3a^2)=20\]

  9. anonymous
    • 4 years ago
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    Yes, that correct.

  10. anonymous
    • 4 years ago
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    It doesn't say the answer is 8.453

  11. anonymous
    • 4 years ago
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    It does, in the solution: a=-10/3(sqrt(3)-3).

  12. anonymous
    • 4 years ago
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    That comes out to approximately 4.2265

  13. anonymous
    • 4 years ago
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    Not 8.453

  14. anonymous
    • 4 years ago
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    You're right I made a mistake, my answer is two times 4.2265.

  15. anonymous
    • 4 years ago
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    OK i will show you how to do the work correctly.

  16. anonymous
    • 4 years ago
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    I am still wondering how I get there though.

  17. anonymous
    • 4 years ago
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    \[3a+\sqrt(3a^2)=20\] \[a(3+\sqrt(3))=20\] \[a=\frac{20}{(3+\sqrt(3))}\]

  18. anonymous
    • 4 years ago
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    From here we rationalize the denominator

  19. anonymous
    • 4 years ago
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    I am confused in the second step.

  20. anonymous
    • 4 years ago
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    \[\frac{20}{3+\sqrt(3)} * \frac{3-\sqrt(3)}{3-\sqrt(3)}\]

  21. anonymous
    • 4 years ago
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    In the second step i simply factored out an a because \[\sqrt(a^2)=a\]

  22. anonymous
    • 4 years ago
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    so it would be \[3a+a \sqrt(3)\]

  23. anonymous
    • 4 years ago
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    Then you can factor out an a here, see?

  24. anonymous
    • 4 years ago
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    okay, i see now thank you very much !

  25. anonymous
    • 4 years ago
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    Do you know how to rationalize the denominator?

  26. anonymous
    • 4 years ago
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    You must do that to get to the final answer

  27. anonymous
    • 4 years ago
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    I do, i need to try it to make sure i get the mechanics of it.

  28. anonymous
    • 4 years ago
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    The numberator should be 60-20sqrt(3), correct? And I am having difficulties with the denominator? Could you help please?

  29. anonymous
    • 4 years ago
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    Nevermind, I figured it out, thank you.

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