Intermediate Algebra (12th Edition)

$(8+r+2t)(8-r-2t)$
$\bf{\text{Solution Outline:}}$ To factor the given expression, $64-(r+2t)^2 ,$ use the factoring of the difference of $2$ squares. $\bf{\text{Solution Details:}}$ Using $a^2-b^2=(a+b)(a-b)$ or the factoring of the difference of $2$ squares, the factored form of the expression above is \begin{array}{l}\require{cancel} [8+(r+2t)][(8-(r+2t)] \\\\= [8+r+2t][(8-r-2t] \\\\= (8+r+2t)(8-r-2t) .\end{array}