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    Could someone please explain this to me?
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    (Original post by razzy02)
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    Could someone please explain this to me?
    What is 81^(1/4), first of all? How can you work out what it is?

    Same logic for the 25 term

    Then see how to put that knowledge together
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    (Original post by SeanFM)
    What is 81^(1/4), first of all? How can you work out what it is?

    Same logic for the 25 term

    Then see how to put that knowledge together
    So 81^(1/4) is 3, and 25 ^ (-1/2) is 50 and then I would multiply them together.
    Is this correct?
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    (Original post by razzy02)
    So 81^(1/4) is 3, and 25 ^ (-1/2) is 50 and then I would multiply them together.
    Is this correct?
    Not quite for the part in bold.

    If, like you correctly calculated,  81^{\frac{1} {4}} = \sqrt[4] {81} = 3
    Then, first of all what would  25^{\frac{1} {2}} be?
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    (Original post by KaylaB)
    Not quite for the part in bold.

    If, like you correctly calculated,  81^{\frac{1} {4}} = \sqrt[4] {81} = 3
    Then, first of all what would  25^{\frac{1} {2}} be?
    It would be 5
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    (Original post by razzy02)
    It would be 5
    Correct , and what does a negative power mean?
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    (Original post by KaylaB)
    Correct , and what does a negative power mean?
    You see that's where I begin to struggle with the question! would I have to flip the fraction upside down?
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    (Original post by razzy02)
    You see that's where I begin to struggle with the question! would I have to flip the fraction upside down?
    Ah I see! For negative indices, it means you do 1 over the x value without the negative sign. It doesn't make much sense when I'm typing it, so I apologise, hopefully this image will show you what I mean


    So in the same way as the graphic above. How else can  25^{-\dfrac{1} {2}} be written?
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    (Original post by KaylaB)
    Ah I see! For negative indices, it means you do 1 over the x value without the negative sign. It doesn't make much sense when I'm typing it, so I apologise, hopefully this image will show you what I mean


    So in the same way as the graphic above. How else can  25^{-\dfrac{1} {2}} be written?
    Thank you so much!! So it would be 1/25^1/2?
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    (Original post by razzy02)
    Thank you so much!! So it would be 1/25^1/2?
    No problem :hat2:

    Yes it would be

    So, if we already know what  25^{\frac{1} {2}} is equal to, then what is  25^{-\frac{1} {2}} = \dfrac{1} {25^\frac{1} {2}} ?
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    (Original post by KaylaB)
    No problem :hat2:

    Yes it would be

    So, if we already know what  25^{\frac{1} {2}} is equal to, then what is  25^{-\frac{1} {2}} = \dfrac{1} {25^\frac{1} {2}} ?
    1/5!!
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    (Original post by razzy02)
    1/5!!
    Yes! Well done! :clap2:

    So finally, can you now tell me what  81^{\frac{1} {4}} \times 25^{-\frac{1} {2}} is equal to? :holmes:
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    (Original post by KaylaB)
    Yes! Well done! :clap2:

    So finally, can you now tell me what  81^{\frac{1} {4}} \times 25^{-\frac{1} {2}} is equal to? :holmes:
    That would be 3 x 1/5 = 0.6 xx
    Thank you so much for all your help!!!
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    (Original post by razzy02)
    That would be 3 x 1/5 = 0.6 xx
    Thank you so much for all your help!!!
    That's correct, good job! :clap2::clap2:

    Glad that I could be of assistance :hat2:
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    to work out something to the power of 1/4 you simply find the square root, then find the square root again. eg 81=9=3.

    when finding out a negative power you need to make it positive by flipping the fraction so there its 25 to the power of -1/2 changes to just 1/2 meaning square root of 25 which is 5.

    Then multiply 3 and 5 to get the final answer.
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    (Original post by keeleighgeorge)
    to work out something to the power of 1/4 you simply find the square root, then find the square root again. eg 81=9=3.

    when finding out a negative power you need to make it positive by flipping the fraction so there its 25 to the power of -1/2 changes to just 1/2 meaning square root of 25 which is 5.

    Then multiply 3 and 5 to get the final answer.
    I'm afraid that isn't correct. See above for how to approach this question
 
 
 
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