The following tough factoring problem contains six terms. It turns out that after some trial and error the best approach to solving this difficult algebra problem is to group the three positive terms and the three negative terms. Then you factor out the Greatest common factor (GCF) in each of the two groups. After doing this, you will get a trinomial which is common to both terms which you can factor out by the distributive property.
You will notice that the common trinomial is also a perfect square which explains the last step in the factorization.