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Homework Help: Evaluate this expression

  1. Feb 24, 2010 #1
    p = 4
    q = -2
    r = 3
    s = -5

    on that basis, evaluate this expression:

    3r - 3p + 5q

    I make it to be -7 (15 - 12 + (-10)
    But my math book says the answer is -13. Can anyone explain where I have gone wrong?
    Thanks
     
  2. jcsd
  3. Feb 24, 2010 #2
    3r - 3p + 5q

    = 3(3) - 3(4) + 5(-2)

    = 9 - 12 -10

    = -13
     
  4. Feb 24, 2010 #3
    Thanks!
     
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