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Extremely stupid question but i want to be 100% sure

  1. Mar 22, 2008 #1
    1. The problem statement, all variables and given/known data

    factorise x^2+3x=2

    2. Relevant equations

    erm...

    3. The attempt at a solution

    (x+2)(x+1)

    book says

    (x+1)(x+2)

    aren't those answers the same? i know it's a stupid question but i want to make sure i'm getting this right
     
  2. jcsd
  3. Mar 22, 2008 #2

    Hootenanny

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    Gold Member

    Yes, the answers are identical since the multiplication of real numbers is a commutative operation :approve:.
     
  4. Mar 22, 2008 #3
    no idea what that means but thanks for your help
     
  5. Mar 22, 2008 #4
    2*5=5*2
     
  6. Mar 22, 2008 #5
    Look in the front cover or something, it's probably there ...
     
  7. Mar 22, 2008 #6
    By defn of multiplication, you get the commutative property which states that a*b=b*a which tells you that the way you multiply two things has no order. So to answer your question yes, it does not matter which one comes first. Most books not all will list their answers in an increasing order, hence (x+1) comes before (x+2) because 2>1
     
  8. Mar 23, 2008 #7

    dynamicsolo

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    Homework Helper

    I'm assuming there is a typo in your statement and that you meant x^2 + 3x + 2 , in which case the factors are (x+2)(x+1) or (x+1)(x+2). The equation x^2 + 3x = 2 would lead to very different factors...
     
  9. Mar 23, 2008 #8

    yes... didn't notice that
     
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