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Homework Help: Alegbra 2

  1. Aug 15, 2010 #1
    1. The problem statement, all variables and given/known data

    Express in simplest form.
    1/2 – 4/d divide by 1/d + 3/2d


    2. Relevant equations

    LCF

    3. The attempt at a solution

    I know the LCD is 2d. But would you multiply this to the equation
     
  2. jcsd
  3. Aug 15, 2010 #2

    danago

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    Gold Member

    You can multiply it as long as you do it to the numerator and the denominator. i.e.:

    [tex]
    \frac{\frac{1}{2}-\frac{4}{d}}{\frac{1}{d}+\frac{3}{2d}} \times \frac{2d}{2d}
    [/tex]

    Also, what you have there isn't really an equation. It is only an equation if there is an equals symbol somewhere.
     
  4. Aug 15, 2010 #3
    Okay, but if you multiply the LCD which is 2d would you multiply 2d to 1/2, 4/d, 1/d and 3/2d

    If so, i got 2d/4d - 8d/2d divided by 2d/2d^2 + 6d/2d^2, is this right?
     
  5. Aug 15, 2010 #4

    danago

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    Gold Member

    Yes you do multiply 2d by 1/2, 4/d, 1/d and 3/2d, but im not quite sure what you have done there.


    [tex]\frac{1}{2}\times 2d = d [/tex]
    [tex]\frac{4}{d}\times 2d = 8 [/tex]
    [tex]\frac{1}{d}\times 2d = 2 [/tex]
    [tex]\frac{3}{2d}\times 2d = 3[/tex]
     
  6. Aug 15, 2010 #5
    Okay, i understand now. The final answer is d - 8/ 5, thanks a lot
     
  7. Aug 15, 2010 #6

    danago

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    Gold Member

    Yes, that is correct :smile:

    As a side note, you should probably try to pay more attention to use of brackets. d-8/5 could be interpreted as d-(8/5) or as (d-8)/5, which are two completely different expressions.
     
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