Learn How to Factor a Quadratic in Your Head When a is not Equal to One

The video tutorial demonstrates how to factor a trinomial expression. It begins by explaining the importance of making the leading coefficient positive and factoring out a negative one. The instructor then breaks down the expression into two factors, considering different combinations to achieve the correct middle term. The process is verified by checking the multiplication of inner and outer terms. The tutorial concludes with a successful factorization of the trinomial using mental calculations.

List the different cases considered for factoring the expression and explain why only two cases were valid.

How does the middle term's sign affect the factoring process?