#### Answer

$(5x+3y)^2$

#### Work Step by Step

The first term is $5x$ squared, the last term is $3y$ squared, and the middle term is twice the product of these two terms. Now we can factor the trinomial into a binomial squared.
$25x^2+30xy+9y^2$
$=(5x+3y)(5x+3y)$
$=(5x+3y)^2$