Algebra 2 Common Core

$$3(m+\sqrt 3)(m-\sqrt 3)$$
Factor $$3m^{2}-9.$$ First factor out a $3$: $$3(m^{2}-3)$$ Find two numbers that are factors of $-3$ and sum to $0$: $$(\sqrt 3)(-\sqrt 3)=-3;\space \sqrt 3-\sqrt 3=0.$$ The polynomial is a product of two binomials: $$3(m^{2}-3)=3(m+\sqrt 3)(m-\sqrt 3).$$