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Math Help - Solving this probem...

  1. #1
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    Unhappy Solving this probem...

    √(2x-1) - √(x+3) = 1
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  2. #2
    MHF Contributor
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    Quote Originally Posted by HappyFeet View Post
    √(2x-1) - √(x+3) = 1
    Hi

    First you have to define the values of x for which √(2x-1) and √(x+3) are defined : [1/2 , +oo[

    Then
    √(2x-1) - √(x+3) = 1
    √(2x-1) = 1 - √(x+3)
    Square
    2x-1 = x+4 - 2√(x+3)
    x-5 = 2√(x+3)
    Square
    (x-5) = 4(x+3)
    x-14x+13=0
    (x-1)(x-13)=0
    x=1 or x=13

    You have now to verify by substituting the two values in the equation (because all the previous equations are not equivalent)
    x=1 is not a solution
    x=13 is a solution, it is the only one
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