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Math Help - simultaneous equations

  1. #1
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    simultaneous equations

    x-y=0
    x^2 + y^2= 18

    where do I start
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  2. #2
    MHF Contributor red_dog's Avatar
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    From the first equation x=y.
    Plug x in the second and solve for y. Then find x.
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  3. #3
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    thanks but

    I understand that bit and the answer is ovbious but I'm unsure of how to get 3 and show how I did from x and y.
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  4. #4
    Forum Admin topsquark's Avatar
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    Quote Originally Posted by lra11 View Post
    I understand that bit and the answer is ovbious but I'm unsure of how to get 3 and show how I did from x and y.
    x - y = 0

    x^2 + y^2 = 18

    Solve the top equation for y:
    y = x

    Insert this into the second equation:
    x^2 + (x)^2 = 18

    Solve for x. When you are done, put these x values into the y = x equation to get your y values.

    -Dan
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  5. #5
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    dumb moment

    thanks I've got it.I was having a bit of a stupid moment. thanks for the help
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