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    A box in the shape of a cuboid has a height of x cm. The length is double the height. The width of the box is 2cm more than the height. The volume of the box is 400cm^3

    Show that x^3+2x^2=200cm^3

    ok for some reason I only manage to get down to x^3+2=200cm^3 or even x^3+4x^2=200cm^3 so someone please shed some light lmao im not thinking straight
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    The cuboid has height x.

    The length is 2x.

    The width is (x+2)

    Therefore, the volume = x(2x)(x+2) = (2x^2)(x+2) = 2x^3 + 4x^2.

    We know the volume to be 400cm^3, so 2x^3 + 4x^2 = 400.

    Divide everything by 2, and x^3 + 2x^2 = 200cm^3.
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    Hope this helps!
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    (Original post by barney_rs)
    the cuboid has height x.

    The length is 2x.

    The width is (x+2)

    therefore, the volume = x(2x)(x+2) = (2x^2)(x+2) = 2x^3 + 4x^2.

    We know the volume to be 400cm^3, so 2x^3 + 4x^2 = 400.

    Divide everything by 2, and x^3 + 2x^2 = 200cm^3.
    omg thank you so much i got there in the end after 10 minutes thank you
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    Height = x
    Length = 2x
    Width = x + 2

    Volume = x(x+2)*2x
    = (x^2+2x)*(2x)
    = 2x^3+4x^2

    Hence 2x^3+4x^2=400cm^3 - Here you want to divide EVERYTHING in the equation by two hence giving you the answer the question wants. Hope this helps! x^3+2x^2=200cm^3
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    (Original post by danielwinstanley)
    height = x
    length = 2x
    width = x + 2

    volume = x(x+2)*2x
    = (x^2+2x)*(2x)
    = 2x^3+4x^2

    hence 2x^3+4x^2=400cm^3 - here you want to divide everything in the equation by two hence giving you the answer the question wants. Hope this helps! X^3+2x^2=200cm^3
    thank you sm
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    Lol You clearly forget to press shift on the last 1 in the title :lol:
 
 
 
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