Question 227530
The reason you're stuck is that you're finished (except to simplify the second factor)!<br>
Whenever you factor you should start by factoring out the Greatest Common Factor (GCF) if it is not a 1. As long as you do this, the second factor of the Sum (or Difference) of Cubes pattern is inherently unfactorable. In other words, as long as the GCF has been taken care of, there is never a point in trying to factor the {{{a^2 - ab + b^2}}} factor. (If you don't believe me, try to factor {{{a^2 - ab + b^2}}}! You won't succeed unless you use irrational numbers.)<br>
Your GCF is 1 so:
{{{1331c^3 + 512d^3 = (11c)^3 + (8d)^3 = (11c + 8d)((11c)^2 - (11c)(8d) + (8d)^2) = (11c + 8d)(121c^2 - 88cd + 64d^2)}}}