## Intermediate Algebra (6th Edition)

$(3x+y-5)(3x+y+5)$
Using $a^2-b^2=(a+b)(a-b)$ or the factoring of the difference of two squares, then, \begin{array}{l} (3x+y)^2-25 \\= [(3x+y)-5][(3x+y)+5] \\= (3x+y-5)(3x+y+5) .\end{array}