Hello!We can factor the given expression using the following special factoring formula,Difference of Squares Factoring:[tex]a^{2}-b^{2}=(a+b)*(a-b)[/tex]So, for the given expression we have that:[tex]a=\sqrt{x^{2} }=x\\b=\sqrt{16}=4[/tex]Therefore,[tex]x^{2}-16=(x+4)*(x-4)=x*x-4*x+4*x-16=x^{2}-16[/tex]Have a nice day!