algebra 2, algebra 2, algebra 2????

algebra 2 help!!!!!!! please?

how to expand this binomial?? (x – y^5)^3?

thanks

8 Answers

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  • 9 years ago
    Best Answer

    (x-y^5)^3

    = (x-y^5) x (x-y^5) x (x-y^5)

    = (x-y x y x y x y x y ) x (x-y x y x y x y x y ) x (x-y x y x y x y x y )

  • Sepia
    Lv 7
    6 years ago

    (x - y^5)^3

    = x^3 - 3x^2y^5 + 3xy^10 - y^15

  • 9 years ago

    For expanding cubic binomials the general formula is as follows:

    (a + b) ^ 3 = a^3 + 3*a^2*b^1 + 3*a^1*b^2 + b^3

    In your case, a is x and b is -y^5

    So

    (x - y^5)^3 = x^3 + 3*x^2*(-y^5)^1 + 3*x^1*(-y^5)^2 + (-y^5)^3

    Simplified:

    =x^3 - 3x^2*y^5 + 3x*y^10 - y^15

    :D

  • 9 years ago

    Take your time, multiply each term and then combine like terms.

    (x - y^5)^3 = (x - y^5)(x - y^5)(x - y^5)

    It's easier to multiply only two expressions at a time.

    (x - y^5)(x^2 - 2xy^5 + y^10)

    x^3 - 2x^2 y^5 + xy^10 - x^2 y^5 + 2xy^10 - y^15

    Combining terms

    x^3 - 3x^2 y^5 + 3xy^10 - y^15

    WOW!!

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  • 9 years ago

    Since it is a quantity to the third power, multiply it by itself three times. (x - y^5)(x - y^5)(x - y^5) so you get (x^2 - 2xy^5 + y^10)(x - y^5) which then expands to:

    x^3 - 2x^2y^5 + xy^10 - x^2y^5 + 2xy^10 - y^15

  • TBT
    Lv 7
    9 years ago

    since

    (x-y)^3 = x^3 -3x^2y +3xy^2 -y^3

    replace y with y^5 and you ge the answer.

    Source(s): my brain
  • 9 years ago

    (x – y^5)^3

    =x3 – y15

    Source(s): my brain
  • Anonymous
    9 years ago

    (x-y^5)(x-y^5)(x-y^5)

    =(x^2-2xy^5+y^10)(x-y^5)

    =(x^3-2x^2y^5+xy^10-x^2-y^5+2xy^10-y^15)

    =x^3-3x^2y^5+3xy^10-y^15

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