Question 218381
Watch out
{{{(x+3)(x^2+9) }}} does NOT equal {{{x^3+27}}}
{{{(x+3)(x^2+9) }}} 
{{{x(x^2+9) + 3(x^2+9)}}}
{{{x^3 + 9x + 3x^2 + 27}}}
{{{x^3 + 3x^2 +9x + 27}}}
Now that you see that. can you do the second one yourself?


{{{12/(x +3) = x/ (x^3 + 27)}}}

The factorization of sum to cubes is given here --> http://www.cliffsnotes.com/WileyCDA/CliffsReviewTopic/Sum-or-Difference-of-Cubes.topicArticleId-38949,articleId-38892.html