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    I have a feeling this is a really obvious one but I can't seem to get it..

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    (Original post by creativebuzz)
    I have a feeling this is a really obvious one but I can't seem to get it..

    Simultaneous equations?
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    (Original post by usycool1)
    Simultaneous equations?
    Well I made them equal to each other:

    9x=3x

    but then the 3x cancels out to give you

    3=0

    :/
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    (Original post by creativebuzz)
    but then the 3x cancels out to give you
    What do you mean by cancels out?
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    (Original post by creativebuzz)
    Well I made them equal to each other:

    9x=3x

    but then the 3x cancels out to give you

    3=0

    :/
    Ah never mind, I see what you've done (divided through by 3x?). If so, instead subtract both sides by 3x so that you get 6x = 0. Then solving for x, you get x = 0.

    By dividing though by x (or 3x), you essentially divide through by zero which ruins things.

    (Also, just as an aside, 3x/3x = 1 )
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    It's asking to show that (x, y) is (0, 0) so you can make the equations equal to each other to get 9x=3x.
    Then for what value of x would this equation hold?
    Next, what value of y do you get when you substitute the newly found value of x into either equation?
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    (Original post by usycool1)
    Ah never mind, I see what you've done (divided through by 3x?). If so, instead subtract both sides by 3x so that you get 6x = 0. Then solving for x, you get x = 0.

    By dividing though by x (or 3x), you essentially divide through by zero which ruins things.

    (Also, just as an aside, 3x/3x = 1 )
    Omg subtracting, of course! How obvious ariejkhjGH ugh that's so annoying! ahah, thank you so much!

    If you don't mind, could you see where I went wrong in these two questions (sorry about the blurry photos and my messy handwriting) :P


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    (Original post by creativebuzz)
    Omg subtracting, of course! How obvious ariejkhjGH ugh that's so annoying! ahah, thank you so much!

    If you don't mind, could you see where I went wrong in these two questions (sorry about the blurry photos and my messy handwriting) :P


    For the first one, it looks like what you've done is fine so far. Now just take out a factor of (x+1)^{-\frac{1}{2}} and play around and you should get it.

    For the second one, it looks like you've got the numerator the wrong way round - it should be u'v - uv' whereas you've done uv' - u'v
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    (Original post by usycool1)
    For the first one, it looks like what you've done is fine so far. Now just take out a factor of (x+1)^{-\frac{1}{2}} and play around and you should get it.

    For the second one, it looks like you've got the numerator the wrong way round - it should be u'v - uv' whereas you've done uv' - u'v

    As for the first one, I've tried factoring (x+1)^-1/2 out and playing around with the numbers but I still can't seem to get the right answer... :/
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    (Original post by creativebuzz)
    As for the first one, I've tried factoring (x+1)^-1/2 out and playing around with the numbers but I still can't seem to get the right answer... :/
    Post your working?
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    (Original post by usycool1)
    Post your working?
    I managed to get question 1 in the end! So thanks!


    But as for question 2, I can't seem to get it in the right form...

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    (Original post by creativebuzz)
    I managed to get question 1 in the end! So thanks!


    But as for question 2, I can't seem to get it in the right form...

    Nice.

    You've made a mistake when going from the first line to the second. x^3(2x) \not= 6x^4 :no:
 
 
 
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