Question

how did the expression:
(x-2)^3 - 8y^3
when expanded became:
(x-2-2y)[(x^2-4x+4)+2(xy-2y)+4y^2]?

Help please?

Answer 1

they are using the formula

\[\Large a^3 - b^3 = (a-b)(a^2 + ab + b^2)\]

difference of cubes formula

Answer 2

in this case

a = x-2
b = 2y ... since (2y)^3 = 8y^3

Answer 3

let me try it. :D

Answer 4

alright

Answer 5

I GOT IT. thanks a lot! :)

Answer 6

you're welcome