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Math Help - Solve the system by addition

  1. #1
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    Solve the system by addition

    5x 3y = 13
    4x 3y = 11


    Can someone tell me if I did this right.
    I multiply the first equation by -1 to get (-5x + 3y = -13)

    -5x + 3y = -13
    4x - 3y = 11
    -1x = -2
    x= 2

    When I try to solve for "y" I get y =-1 so is that right?
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  2. #2
    is up to his old tricks again! Jhevon's Avatar
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    Quote Originally Posted by Patience View Post
    5x 3y = 13
    4x 3y = 11


    Can someone tell me if I did this right.
    I multiply the first equation by -1 to get (-5x + 3y = -13)

    -5x + 3y = -13
    4x - 3y = 11
    -1x = -2
    x= 2

    When I try to solve for "y" I get y =-1 so is that right?
    you are correct!

    good job!
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  3. #3
    is up to his old tricks again! Jhevon's Avatar
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    you know, you can see for yourself that your answers were correct.

    you could plug in the values you got for x and y on the left side of BOTH equations and see if you get the answers on the right.

    i say both, because i have seen solutions where the answers work for one equation but not the other--and so, the system was not solved
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