Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Easy Question

  1. Oct 13, 2005 #1
    Apparently I've forgotten how to simplify algebraic fractions. I included the problem as a picture.
    http://community.webshots.com/photo/461491683/476214616XrKOZJ#"
    I can't figure out how they went from the red box and then to the green box and then the blue box. Obviously, I understand from the green to purple, but the rest is puzzling me. Any help would be appreciated.
     
    Last edited by a moderator: Apr 21, 2017
  2. jcsd
  3. Oct 13, 2005 #2
    sorry, fixed the pic
     
  4. Oct 13, 2005 #3

    mezarashi

    User Avatar
    Homework Helper

    From red to green, they did this:

    [tex] \frac{2}{2+h} -1 = \frac{2}{2+h} - 1\frac{(2+h)}{(2+h)} = \frac{2}{2+h} - \frac{2+h}{2+h}[/tex]

    Multiplying by fractions in the form of b/b is equal to multiplication by 1.

    From purple to blue:

    [tex] \frac{\frac{-h}{2+h}}{h} = \frac{-h}{h(2+h)}[/tex]

    They just divided the top part by h, the same way you would do: [tex]\frac{\frac{1}{3}}{2} = \frac{1}{3\times2}[/tex]
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook