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Math Help - Solving simultaneous equations using substitution method.

  1. #1
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    Exclamation Solving simultaneous equations using substitution method.

    I need help with the following problem. I forgot how to do these and this assignment is due tomorrow. Any help would be greatly appreciated!

    Solve by substitution method:

    x + y = 2
    y = x^2 - 4
    Last edited by mr fantastic; December 8th 2009 at 04:09 AM. Reason: Changed post title
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  2. #2
    Super Member Bacterius's Avatar
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    Substitute the second one into the first one. Thus, you get :

    x + (x^2 - 4) = 2

    x + x^2 = 6

    x^2 + x - 6 = 0

    Now solve for x using the factorization method or the quadratic formula, then substitute back the x's into the first equation to find the y's
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  3. #3
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    Thanks alot. Got it now. =]
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