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Math Help - Answer in Algebra book doesn't match mine!

  1. #1
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    Answer in Algebra book doesn't match mine!

    To make a long story short, I'm in the "Solving Systems of Equations Algebraically" section and the instructions want me to use the Elimination Method. The problem is: 8x-4y=16 over 4x+5y=22

    For the x variable I got 7 as my answer, but the book says it should be 3. Am I right or is the book right?

    -Thanks
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  2. #2
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by HazelHybrid View Post
    To make a long story short, I'm in the "Solving Systems of Equations Algebraically" section and the instructions want me to use the Elimination Method. The problem is: 8x-4y=16 over 4x+5y=22

    For the x variable I got 7 as my answer, but the book says it should be 3. Am I right or is the book right?

    -Thanks
    the book is right

    x = 3, y = 2

    you can check this yourself
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  3. #3
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    8x-4y=16
    4x+5y=22

    Now, you want to make this such that you can cancel out x or y so you can solve for the other. Once you solve for one of the variables, you can plug it in and easily solve for the other.

    8x-4y=16
    (4x+5y=22)*-2

    8x-4y=16
    -8x-10y=-44

    -14y=-28
    y=2

    Plug in y=2 into the original equation and solve for x. x=3
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