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← Finding the LCD 2 - Visualizing Algebra

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Showing Revision 2 created 05/25/2016 by Udacity Robot.

  1. The LCD is 2 times u minus 3 times u plus 3. Fantastic work if you figured that
  2. one out. Again, I don't expect you to get that right on your first try, or even
  3. maybe at all. Let's see how we do it. We know u squared minus 9 is a difference
  4. of two perfect squares. So we can factor this as u plus 3 times u minus 3. So we
  5. can rewrite this first fraction like this. For the second denominator we have a
  6. common factor of 2. So we can factor that out. Now that we have factored
  7. denominators, we can use our factor tree method. These two denominators share a
  8. common factor of u minus 3, and the other factor for this one is u plus 3, while
  9. the other factor for this one is positive 2. And there it is. We multiply all
  10. these together to get 2 times u plus 3 times u minus 3, our LCD.