## College Algebra (11th Edition)

$9k^2-30km+25m^2$
$\bf{\text{Solution Outline:}}$ To simplify the given expression, $(3k-5m)^2 ,$ use the special product on squaring binomials. $\bf{\text{Solution Details:}}$ Using the square of a binomial which is given by $(a+b)^2=a^2+2ab+b^2$ or by $(a-b)^2=a^2-2ab+b^2,$ the expression above is equivalent to \begin{array}{l}\require{cancel} (3k)^2-2(3k)(5m)+(5m)^2 \\\\= 9k^2-30km+25m^2 .\end{array}