Answer:
2(r+4)(r-4)
Step-by-step explanation
First, you want to factor out 2 from both terms, which gives you 2(r^2-16). Then you want to recognize that (r^2-16) is factorable into 2 terms. If you multiply (r+4) by (r-4) then you are given (r^2-16) as a result.
