Chan09 wrote:Need some help:
Hint is (a-b)^3 and answer is (a-b)(a^2+ab+b^2)
(a-b)(a-b)(a-b) but then a^2-b^2= (a-b)(a+b)
Hi, usually the standard way to prove that a^3-b^3=(a-b)(a^2+ab+b^2)
is to expand (a-b)(a^2+ab+b^2)=a^3+a^2b+ab^2-a^2b-ab^2-b^3 and cancel out the terms.
Using hint is possible too,
Hope it helps!
I have also typed out the solution in LaTeX on my website:
http://mathtuition88.wordpress.com/2013 ... atex-a-b3/