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Thread: Definitely needed math help :(

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    Default Definitely needed math help :(

    It's my middle of the year exam (Mid Exam, or Mid Term) and I'm taking algebra/trigonometry but I need some help.

    For one I'll just post a problem

    Which expression is equivalent to (√(7) + √(2)) / (√(7) - √(2))

    The answer is C but i need to know how to get to that answer without just plugging it into my calculator(plug in all the choices).

    A) (11 + √(2)) / 14
    B) 9/5
    C) (9 + 2√(14)) / 5
    D) - 1

    Edit: I understand that problem now, go to my next post for the new one.
    Should of just taken a picture but whatever, I'd really appreciate if someone could add my msn aarondawg14@yahoo.com and give me some more help

    Could give you something in RS.
    Last edited by Camaro'; 01-26-2012 at 02:51 AM.

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    Try plugging this: (√(7) + √(2)) / (√(7) - √(2))

    ... into ...

    This: http://www.wolframalpha.com

    ... and then see if what it throws back at you gives you any clues.
    Last edited by NickMystre; 01-26-2012 at 02:44 AM.
    Ciao
    NM

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    I did that earlier which gave me the answer I needed, but I still am not sure how to get that answer.

    I multiply both the denominator and numerator by √7 + √2 and the bottom comes out to be 7 - 2 which is 5, but I don't understand how they get the numerator.

    Edit: Wow, I'm stupid. I understand this problem. Someone here is helping me on MSN. If i get anymore problems I'll be sure to post them.
    Last edited by Camaro'; 01-26-2012 at 02:53 AM.

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    Try these, they should give you clues to re-writing the problem. If not, try Googling for the rules that govern these types of calculations.

    http://www.mathwords.com/s/square_root_rules.htm
    http://www.mathwords.com/r/radical_rules.htm
    http://www.mathwords.com/e/exponent_rules.htm

    E: I think exponent rules should definitely give you the answer and then it's a case of simplifying - or arranging into the solution given.
    Last edited by NickMystre; 01-26-2012 at 02:56 AM.
    Ciao
    NM

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    Multiply by the conjugate is what it is called, just for a reference.

    "Failure is the opportunity to begin again more intelligently" (Henry Ford)


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    Quote Originally Posted by HyperSecret View Post
    Multiply by the conjugate is what it is called, just for a reference.
    Thanks both of you, I read those pages and I understand the problem now.

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    This program was phenomenal to me when I needed help in algebra many years ago
    http://www.bagatrix.com/algebra.aspx
    http://www.bagatrix.com/trigonometry.aspx

    Might be of use to you

    I plan on using it for linear algebra and finite math in college
    E: Its expensive, so I would ... uhh




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    Quote Originally Posted by R4nd0m View Post
    This program was phenomenal to me when I needed help in algebra many years ago
    http://www.bagatrix.com/algebra.aspx
    http://www.bagatrix.com/trigonometry.aspx

    Might be of use to you

    I plan on using it for linear algebra and finite math in college
    E: Its expensive, so I would ... uhh
    This could just save me

    Checking it out as we speak, will edit this post.

    I've obtained it, looks awesome!
    Last edited by Camaro'; 01-26-2012 at 06:07 AM.

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    Just Surds.

    (√(7) + √(2)) / (√(7) - √(2))

    Simplifies to:

    √9 / √5

    Simplifies to:

    √1.8 (√1 4/5) = √9/5

    But it's midnight i'm fucking tired so idk check
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    Don't you know these equations?






    (√(7) + √(2)) / (√(7) - √(2)) =

    = ( (√(7) + √(2)) * (√(7) + √(2)) ) / ( (√(7) - √(2)) * (√(7) + √(2)) )

    = ( 7 + 2 + 2*√(2)*√(7) ) / ( 7 - 2 ) = ( 9 + 2*√(2)*√(7) ) / 5

    = ( 9 + 2*√(14) ) / 5

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    Quote Originally Posted by Camaro' View Post
    It's my middle of the year exam (Mid Exam, or Mid Term) and I'm taking algebra/trigonometry but I need some help.

    For one I'll just post a problem

    Which expression is equivalent to (?(7) + ?(2)) / (?(7) - ?(2))

    The answer is C but i need to know how to get to that answer without just plugging it into my calculator(plug in all the choices).

    A) (11 + ?(2)) / 14
    B) 9/5
    C) (9 + 2?(14)) / 5
    D) - 1

    Edit: I understand that problem now, go to my next post for the new one.
    Should of just taken a picture but whatever, I'd really appreciate if someone could add my msn aarondawg14@yahoo.com and give me some more help

    Could give you something in RS.
    9/5
    because when we multiply its conjugate then upper part get 9 ans when square rot cancel with square of 7 and as 2. so the sign + make both values 9. and the denominator get 5 because the same procedure we apply but sign - it makes 5.

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    Quote Originally Posted by Camaro' View Post
    It's my middle of the year exam (Mid Exam, or Mid Term) and I'm taking algebra/trigonometry but I need some help.

    For one I'll just post a problem

    Which expression is equivalent to (?(7) + ?(2)) / (?(7) - ?(2))

    The answer is C but i need to know how to get to that answer without just plugging it into my calculator(plug in all the choices).

    A) (11 + ?(2)) / 14
    B) 9/5
    C) (9 + 2?(14)) / 5
    D) - 1

    Edit: I understand that problem now, go to my next post for the new one.
    Should of just taken a picture but whatever, I'd really appreciate if someone could add my msn aarondawg14@yahoo.com and give me some more help

    Could give you something in RS.
    = ( 9 + 2*?(14) ) / 5 just we multiply it conjugate and after applying simple formulas we get this easily

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    lmfao
    took ppl long enough
    soloution:

    Steps- Multiply by conjugate pair to achieve the difference of 2 squares, this cancels out the the surds in the denomuinator, then expand out of the brackets

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    Quote Originally Posted by Anguse View Post
    9/5
    because when we multiply its conjugate then upper part get 9 ans when square rot cancel with square of 7 and as 2. so the sign + make both values 9. and the denominator get 5 because the same procedure we apply but sign - it makes 5.
    Major gravedig, try looking at the date of the last post before posting.
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