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Math Help - Solving Systems Using Elimination

  1. #1
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    Question Solving Systems Using Elimination

    How do you solve the following system using elimination!

    2x-3y=61
    2x+y=-7
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  2. #2
    Senior Member
    Joined
    Nov 2008
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    Good day to you

    Quote Originally Posted by amberkraidich View Post
    How do you solve the following system using elimination!

    2x-3y=61
    2x+y=-7
    E is supposed to mean equation
    (E1) 2x-3y=61

    (E2) 2x+y=-7

    Comparing E1 with E2 you see they both have '+2x' in it. Thus we calculate (E1) - (E2) and you get

    2x-3y - [2x+y]=61 - [-7]

    More calculating

    2x - 3y - 2x -y = 61 + 7

    2x - 2x -3y - y = 68

    -3y - y = 68

    -4y = 68

    y = - 17

    how to get x? Use y = - 17 in (E1) for example, then

    (E1) 2x-3*(-17)=61

    2x + 51 = 61

    2x = 10

    x = 5

    Okay?

    Cheers,
    Rapha
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