## Elementary Algebra

$3(n-5)(n+6)$
Using the rules of factoring trinomials to factor the polynomial, we obtain: $3n^{2}+3n-90$ =$3(n^{2}+n-30)$ =$3(n^{2}-5n+6n-30)$ =$3[n(n-5)+6(n-5)]$ =$3(n-5)(n+6)$