## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)

$(x+3)(x+4)(x-4)$
Using factoring by grouping, the factored form of the given expression, $x^3+3x^2-16x-48 ,$ \begin{array}{l} (x^3+3x^2)-(16x+48) \\\\= x^2(x+3)-16(x+3) \\\\= (x+3)(x^2-16) .\end{array} Using $a^2-b^2=(a+b)(a-b)$ or the factoring of the difference of $2$ squares, then the factored form of the expression, $(x+3)(x^2-16)$, is \begin{array}{l} (x+3)(x+4)(x-4) .\end{array}