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    Solve the simultaneous equation y+x=7 and y=x^2+3x-5
    X= or x=
    Y= or y=
    So far I've got:
    X=7-y
    Y=49-14y+y^2+21-3y-5
    Y=y^2+17y+65
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    (Original post by Musicanor)
    Solve the simultaneous equation y+x=7 and y=x^2+3x-5
    X= or x=
    Y= or y=
    So far I've got:
    X=7-y
    Y=49-14y+y^2+21-3y-5
    Y=y^2+17y+65
    Why are you doing it in terms of Y when the second equation is in terms of X.
    Try again but cancel the Ys and solve for X
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    (Original post by Musicanor)
    Solve the simultaneous equation y+x=7 and y=x^2+3x-5
    X= or x=
    Y= or y=
    So far I've got:
    X=7-y
    Y=49-14y+y^2+21-3y-5
    Y=y^2+17y+65
    If you go through this route then re-check your last line and take the y over to the same side as  y^{2} .

    As 'jay' said, it is easier to substitute y instead.
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    (Original post by simon0)
    If you go through this route then re-check your last line and take the y over to the same side as  y^{2} .

    As 'jay' said, it is easier to substitute y instead.
    Thank you for your help
 
 
 
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