You can
put this solution on YOUR website!Well, the brute force way is to just multiply the terms...if the power is much higher, you'll want to avail yourself of the binomial expansion/theorem, which will give you the coefficients you need...anyway, here's what I would do (using the binomial expansion/theorem)...
(2x - 4y)^3 =
(2x)^3 + 3(2x)^2(-4y) + 3(2x)(-4y)^2 + (-4y)^3 =
8x^3 - 48x^2y + 96xy^2 - 64y^3
