![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
First factor the each term in the expression.
\3n = 3 · n.
\9 = 3 · 3.
\The GCF is the product of the common prime factors in each term.
\GCF = 3
\![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step2.JPG\")
Write each term as a product of the GCF and its remaining factors.
\3n + 9 = 3(n) + 3(3)
\Combine like terms uisng distribuitve property: ab + ac = a(b + c)
\3n + 9 = 3(n + 3)![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
Simplified expression is 3(n + 3).