Here is a site that clearly and thoroughly explains factoring trinomials, including those with leading coefficient other than 1. There are example problems solved, problems for the student to attempt, and answers to the student problems....

Thirty-nine problems present a variety of problems working with factoring quadratic trinomials. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View...

Thirty-six problems present a variety of problems working with factoring polynomials. They are given with each step to the solution cleverly revealed one at a time. You can work each step of the problem then click the "View Solution"...

From pulling out the common factors of a polynomial to giving hints on how to factor a trinomial that does not have a leading coefficient of 1, a comprehensive tutorial for factoring polynomials is given as well as practice, interactive...

This is the first of two algebra lesson plans from Annenberg Learning. Find plans to teach learners how to factor trinomials. This lesson plan is part of a larger workshop for teachers that offer insights into teaching algebra.

Contains a few example problems on factoring polynomials with a given root.