Trying to factor all trinomials using guess and check can be time consuming. If, after half a minute, you're still having trouble factoring a trinomial, the AC method is a step-by-step procedure that will get the job done. In the second set of videos you'll practice factoring a special binomial using the "difference of two squares". This material is covered on pages 231-240 in the Engaging Algebra text.
5.7 Factoring with the AC Method
After these videos you'll be able to factor trinomials using the AC method.
5.8 Factoring Special Forms
After this lesson you'll be able to factor binomials using the difference of two squares.