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Math Help - Linear Equations through Elimination?

  1. #1
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    Linear Equations through Elimination?

    NO idea how to do this. Can someone please help me?

    {-x + 3y = -1
    x- 2y = 2

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  2. #2
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    y=1

    x=4
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  3. #3
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    ???

    How did you get that?
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  4. #4
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    Quote Originally Posted by SoobadatMath. View Post
    NO idea how to do this. Can someone please help me?

    {-x + 3y = -1
    x- 2y = 2

    add the two equations, term for term ...

    -x + 3y = -1
    x - 2y = 2
    ------------
    0 + y = 1 ... note that the x terms cancel

    now sub 1 in for y in either equation and solve for x.
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  5. #5
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    So then x + 3y = -4
    y + x = 0
    ???????????????????
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  6. #6
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    Quote Originally Posted by SoobadatMath. View Post
    So then x + 3y = -4
    y + x = 0
    ???????????????????
    What are you doing ?

    You were told that y = 1.
    So replace the y with 1 in one of the equations, then solve for x.
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  7. #7
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    Quote Originally Posted by SoobadatMath. View Post
    So then x + 3y = -4
    y + x = 0
    ???????????????????
    new system ...

    x + 3y = -4
    y + x = 0

    multiply every term in the second equation by -1 ...

    x + 3y = -4
    -x - y = 0
    -------------

    add 'em up and solve.
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  8. #8
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    x + 3y = -4 [1]
    y + x = 0 [2]
    If that's a new system, then from [2]: y = -x
    So [1]: x - 3x = -4
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