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    x^2 + 2Kx -7 =0

    i get x= (root k^2-7 ) -k
    that seems so wrong
    what do you get?
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    x=-k+/-(k^2+7)^1/2
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    (-2k+/-(4k^2+28)^1/2)/2
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    -k±√(k²+7)
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    (Original post by Fermat)
    -k±√(k²+7)

    Yep, thats the same result as me.
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    I don't get it, what am I doing wrong?
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    (Original post by hitchhiker_13)
    I don't get it, what am I doing wrong?

    Type out your working and I'll try and see an error. You will probably see what it is when you work through the question again.
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    Is the equation for quadratics not (-b +/- (b^2-4ac)^1/2)/2a?
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    (Original post by hitchhiker_13)
    Is the equation for quadratics not (-b +/- (b^2-4ac)^1/2)/2a?


    Yes but in this case it's easier to complete the square.
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    (Original post by Ralfskini)
    Yes but in this case it's easier to complete the square.

    Ah ok, it's actually the same answer, just yours is simpler.
    Thanks.
 
 
 
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