How do you expand the binomial (4x-4y)^3?

1 Answer
Oct 23, 2016

64x^3-192x^2y+192xy^2-64y^3

Explanation:

The cubic difference of a binomial is:
color(red)((a-b)^3=a^3-3a^2b+3ab^2-b^

(4x-4y)^3=color(red)((4x)^3-3(4x)^2(4y)+3(4x)(4y)^2_(4y)^3)
(4x-4y)^3=64x^3-3(16x^2)(4y)+3(4x)(16y^2)-64y^3
(4x-4y)^3=64x^3-192x^2y+192xy^2-64y^3

There is not like polynomials in the above expanded form
hint: color(blue)(x^2y!=xy^2)