1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Basic Arithmetic Problem!

  1. Aug 5, 2007 #1
    1. The problem statement, all variables and given/known data

    LCD of 5/2x and 7/5x3y

    2. Relevant equations

    Lowest common denominator is also lowest common multiple:

    (5)(x)(3)(y) =

    I figured, the lowest common multiple of 2x and 5x3y is 10x3y. For some reason, my book shows the answer as 10x^2(y)!

    3. The attempt at a solution

    At this point, I don't know why I didn't come up with the same solution as the book.

    This is from the Pre-Algebra text "Preparation for Algebra" Nanney/Cable. I bought this from my college to brush up on a lot of fundamental skills I'd forgotten and this was an exercise in the beginning of the book. Is it a typo or am I just going crazy?
    Last edited: Aug 5, 2007
  2. jcsd
  3. Aug 5, 2007 #2


    User Avatar
    Homework Helper
    Education Advisor
    Gold Member

    Do you mean
    [tex] \[
    \frac{5}{{2x}}\quad and\quad \frac{7}{{5x3y}}

    If so, then LCD is [tex] \[
    2 \cdot 3 \cdot 5 \cdot xy
  4. Aug 5, 2007 #3
    Yeah, I agree with 30xy if the denominators are 2x and 15xy each...
  5. Aug 6, 2007 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    It's either a typo or poor quality printing.

    Does [itex]5x^2y [/itex] look a little bit like [itex]5x3y[/itex]? I'll bet the book meant the former.
  6. Aug 6, 2007 #5

    Yes, that's how I meant it. But I also agree with Gokul43201 in that it might be a typo or poor printing because it seems that all the other exercises in the section have a certain likeness to it... this one seemed off.

    Thanks for the help.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Basic Arithmetic Problem!