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Quadratics part2

  1. Nov 4, 2004 #1

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    Just check these over and seen if there correct, thanks

    #1
    1-x=0.5x^2
    Times everything by 2
    2-2x=1x^2
    Move it over
    -1x^2 - 2x + 2=0
    a=-1
    b=-2
    c=2

    x=2 +/- root -2 - 4(-1)(2) all over -2

    x=2 t/- root 6 all over -2

    x=-1 +/- root -3

    #2
    2-x=x^2 + x
    -x^2 -x -x + 2=0
    a=-1
    b=-2
    c=2
    same thing as #1 so if that correct then I guess this will be :rolleyes:

    #3
    6(2-x)=3x^2 + 6x
    I warn you, this could be wrong
    12-6x=yada yada
    -3x^2 -6x -6x + 12=0
    a=-3
    b=-6
    c=12

    x=6 +/- root -6 - 4(-3)(12) all over -6

    x=6 +/- root 138 all over -6

    x= -1 +/- root 23

    Thanks for any help
     
  2. jcsd
  3. Nov 4, 2004 #2

    NateTG

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    I think you've got some algebra errors in there:
    [tex]6(2-x)=3x^2-6x[/tex]
    Divide both sides by [tex]3[/tex]
    [tex]2(2-x)=x^2-2x[/tex]
    multiply out
    [tex]4-2x=x^2-2x[/tex]
    add [tex]2x-4[/tex] to both sides
    [tex]0=x^2-4[/tex]
    [tex]x = \pm 2[/tex]
     
  4. Nov 4, 2004 #3
    Since you have [tex]-6x-6x[/tex], [tex]b=-12[/tex]

    I think the original equation was [tex]6(2-x)=3x^2+6x[/tex], not [tex]6(2-x)=3x^2-6x[/tex]
     
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