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I need help with homework

  1. Sep 17, 2009 #1
    Hi im an 8th grader i gotta do my homework lol help me fast plz!
    How do you do a problem like this??
    2 -2
    --
    3
     
  2. jcsd
  3. Sep 17, 2009 #2
    so what this question is 2 over 3 with a negetive exponent. sorry about that/
     
  4. Sep 17, 2009 #3

    symbolipoint

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    Your question is not precise. Try either good typesetting or use clear text-based notation; otherwise express clearly in writing what help you want.

    How is the exponent applied? Is it applied to the entire fraction or is it applied just to the numerator?
     
  5. Sep 17, 2009 #4
    it is only applied in the numerator.
    2 over 3 with an negative exponent next to the 2.
    How the heck do you do this :(
    oh and the negetive exponent is -2.
     
  6. Sep 17, 2009 #5

    Integral

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    Note that I have moved your post.

    Not sure what your number is. Do you mean:

    [tex] ({ \frac 2 3 })^{-2}} [/tex]
     
  7. Sep 17, 2009 #6
    YES!! THAT IS EXACTLY WHAT I MEAN :)
    Can any1 help me with this now? :)
     
  8. Sep 17, 2009 #7

    Integral

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    Ok so you have:

    [tex] \frac {2^{-2}} 3 [/tex]

    What do you know about negitive exponents?
     
  9. Sep 17, 2009 #8
    I do know that you have to multiply it with the numerator and you get a negetive answer.

    so -2 x 2 = -4
    and it would be
    -4 over 3
     
  10. Sep 17, 2009 #9

    Integral

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    No, that will not work. So do you understand the meaning of [itex] 2^{-1} [/itex]?
     
  11. Sep 17, 2009 #10
    isnt [itex] 2^{-1}[/itex] = -2?

    Explain other details please
     
  12. Sep 17, 2009 #11

    Integral

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    Nope!

    [tex] 2^{-1} = \frac 1 2[/tex]
     
  13. Sep 17, 2009 #12

    Math Is Hard

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  14. Sep 17, 2009 #13
    Understanding the meaning of 2-1 is critical to handling any question of this type and your original question in particular.

    What does your instructor/notes/text give as the definition of a-n?

    How would you apply that definition to 2-1?

    --Elucidus
     
  15. Sep 17, 2009 #14
    How?
     
  16. Sep 17, 2009 #15

    Math Is Hard

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    Look at the link I posted.
     
  17. Sep 17, 2009 #16
    She told me to multiply the numerator with the exponent i think, and the answer would be a negative number
     
  18. Sep 17, 2009 #17
    Oh and she said something about Reciprocal
     
  19. Sep 17, 2009 #18
    From the Product Rule of Exponents we want

    [tex]2^1 \cdot 2^{-1} = 2^{1+(-1)} = 2^0 = 1[/tex].

    But 21 = 2 so

    [tex]2 \cdot 2^{-1} = 1[/tex] implies

    [tex]2^{-1} = \frac{1}{2}[/tex]

    by dividing both sides by 2.

    --Elucidus
     
  20. Sep 17, 2009 #19

    Integral

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    Don't you have a textbook?
     
  21. Sep 17, 2009 #20
    Can you give an example using the problem i posted?
     
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