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Math Help - I've tried and I've tried, but...

  1. #1
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    I've tried and I've tried, but...

    I can't do my homework. Could you please help me?

    I need to solve this one:

    5x x 5^2x+1 = 40

    and this one, too:

    4x^6 - 48 = 4
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  2. #2
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    Quote Originally Posted by Liza88 View Post
    I can't do my homework. Could you please help me?

    I need to solve this one:

    5x x 5^2x+1 = 40

    and this one, too:

    4x^6 - 48 = 4
    Your first equation is unintelligible. Do you mean (5x) 5^{2x + 1} = 40 ? You will need to post it much more clearly.

    For the second, do you mean 4 x^6 - 48 = 4 ? In which case yu have 4 x^6 = 52 \Rightarrow x^6 = \frac{52}{4} = 13. Now take the sixth root of each side.
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  3. #3
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    The first one is supposed to be:

    5X multiply 5power2x+1 = 40

    and the second one:

    5powerx multiply 5power2x+1 = 40

    I can't count neither of those
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  4. #4
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    Quote Originally Posted by Liza88 View Post
    The first one is supposed to be:

    5X multiply 5power2x+1 = 40

    and the second one:

    5powerx multiply 5power2x+1 = 40

    I can't count neither of those
    I don't understand your first question.

    If I read your second question correctly ... (?):

    \begin{aligned}5^x\cdot 5^{2x+1} = 40\\<br />
5 \cdot 5^y \cdot 5^{2x} = 40\\<br />
5^{3x} =8 = 2^3\\<br />
5^x= 2\\<br />
x=\log_5(2)\end{aligned}
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  5. #5
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    Thank you!

    The first one is:

    5X * 5^2X+1 = 40

    I hope that is understandable, I don't know how to write it any other way.
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  6. #6
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    Quote Originally Posted by Liza88 View Post
    Thank you!

    The first one is:

    5X * 5^2X+1 = 40

    I hope that is understandable, I don't know how to write it any other way.
    Do you mean:

    (5x)*(5^(2x)) +1 = 40 ........... or

    (5x)*(5^(2x+1)) = 40 ........... or

    (5x)*(5^2)(x+1) = 40 ........... or

    (5x)*(5^2(x+1)) = 40 ........... ???
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  7. #7
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    Thank you very much, your answer was fine!
    Last edited by mr fantastic; February 5th 2009 at 03:23 PM.
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