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Math Help - Finding real solutions with absolute value

  1. #1
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    Finding real solutions with absolute value

    Here is the equation: |x|^2 + 2|x| -3=0

    The answer is + or - one. I solved it normally disregarding the abs. value and I got 1 and -3.
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    Re: Finding real solutions with absolute value

    Quote Originally Posted by benny92000 View Post
    Here is the equation: |x|^2 + 2|x| -3=0
    The answer is \pm 1.
    Do yo understand it is the same as x^2+2|x|-3=0~?
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    Re: Finding real solutions with absolute value

    Yes. I guess basic reason will take me from there.
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  4. #4
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    Re: Finding real solutions with absolute value

    Let \displaystyle X = |x| so that your equation becomes \displaystyle X^2 + 2X - 3 = 0.

    Solve for \displaystyle X and then use that solution to solve for \displaystyle |x|.
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