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Homework Help: Logarithmic equations

  1. Oct 8, 2006 #1
    If loga^2=x and loga^5=y, find in terms of x and y, expressions for
    a) log2^5
    b) loga^20

    so loga^2 = ____log^2_____

    so log^2 = x * log^a

    Iam not sure where to take it from here or whether I am even going down the right route

    any help/ideas welcome
  2. jcsd
  3. Oct 8, 2006 #2
    is it (___log2^2_____ ) * y ????????
    ( x )
  4. Oct 8, 2006 #3
    would that be the correct way of expressing part a) in terms of x and y????
  5. Oct 8, 2006 #4
    I think the answer to part b) is 2(xy), also is that the right answer to part a) posted above ????
  6. Oct 8, 2006 #5


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    Homework Helper

    You got the answer to part b) right. The answer to part a) is, of course, different.
  7. Oct 8, 2006 #6
    is the answer to part a)

    x ( times y) ???
  8. Oct 8, 2006 #7


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    Homework Helper

    First, you probably mistyped a): did you mean loga^5 instead of log2^5? If so, xy equals something else. Apply the rule loga^b = b*loga and see what xy equals.
  9. Oct 8, 2006 #8
    no for part a), i have to find log2^5 in terms of x and y
    i thought that by working out log2^a and then multiplying loga^5 should give log2^5??
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