Chapter 5 - Section 5.3 - Special Products - Exercise Set - Page 367: 27

$9x^2-4$

Using $(a+b)(a-b)=a^2-b^2$ or the special product of the sum and difference of like terms, the product of the given expression, $ (3x+2)(3x-2) ,$ is \begin{array}{l}\require{cancel} 3x(3x)-2(2) \\\\= 9x^2-4 .\end{array}