Rewrite $x^{6}-36$ as $\left(x^{3}\right)^{2}-6^{2}$. The difference of squares can be factored using the rule: $a^{2}-b^{2}=\left(a-b\right)\left(a+b\right)$. The following polynomials are not factored since they do not have any rational roots: $x^{3}-6,x^{3}+6$.
