little algebra problem

Discussion in 'Math' started by Chrill3, Mar 11, 2010.

  1. Chrill3

    Thread Starter New Member

    Mar 8, 2010
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    0
    I have struggled a while with this one. I dont understand how it comes like this, from the beginning I have R2/(R2+R1+(1/x)) → (x*R2)/(1+x(R2+R1))
    if someone can show me how it can change i will be very glad.
     
    Last edited: Mar 12, 2010
  2. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    5,448
    782
    It can't - plug in some real values for R1, R2 and x and you'll find the two forms are different.

    e.g. let x=5, R1=2 & R2= 3

    R2/(R1+R2+x)=3/10

    but

    x*R2/(1+x(R1+R2))=5*3/(1+25)=15/26
     
  3. Chrill3

    Thread Starter New Member

    Mar 8, 2010
    9
    0
    oh sorry it should be like this = R2/(R2+R1+(1/x)) → (x*R2)/(1+x(R2+R1))
     
  4. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
    5,671
    898
    Multiply the numerator and denominator by x, then rearrange the denominator.

    John
     
  5. Ammaar_Saleem

    New Member

    Mar 26, 2010
    2
    0
    R2/(r2+r1+(1/x))

    just take the lcm of denominator which is x in this case
    now

    r2/(r2*x+r1*x+1)/x

    r2*(x)/(1+x(r1+r2))

    r2x/(1+x(r1+r2))

    thats all
     
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