## Intermediate Algebra (12th Edition)

$(9+x)(81-9x+x^2)$
$\bf{\text{Solution Outline:}}$ To factor the given expression, $729+x^3 ,$ use the factoring of the sum/difference of $2$ cubes. $\bf{\text{Solution Details:}}$ Using $(a\pm b)(a^2\mp ab+b^2)$ or the factoring of the sum/difference of $2$ cubes, the expression above is equivalent to \begin{array}{l}\require{cancel} (9+x)[(9)^2-9(x)+(x)^2] \\\\= (9+x)(81-9x+x^2) .\end{array}