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

$2(2x+3)(7x-1)$
Factoring the $GCF= 2 ,$ the given expression is equivalent to \begin{array}{l}\require{cancel} 28x^2+38x-6 \\\\= 2(14x^2+19x-3) .\end{array} Using the factoring of trinomials in the form $ax^2+bx+c,$ the $\text{ expression }$ \begin{array}{l}\require{cancel} 2(14x^2+19x-3) \end{array} has $ac= 14(-3)=-42$ and $b= 21,-2 .$ Using these $2$ numbers to decompose the middle term of the trinomial expression above results to \begin{array}{l}\require{cancel} 2(14x^2+21x-2x-3) .\end{array} Grouping the first and second terms and the third and fourth terms, the given expression is equivalent to \begin{array}{l}\require{cancel} 2[(14x^2+21x)-(2x+3)] .\end{array} Factoring the $GCF$ in each group results to \begin{array}{l}\require{cancel} 2[7x(2x+3)-(2x+3)] .\end{array} Factoring the $GCF= (t+2)$ of the entire expression above results to \begin{array}{l}\require{cancel} 2[(2x+3)(7x-1)] \\\\= 2(2x+3)(7x-1) .\end{array}