Tyler Wallace's "Beginning and Intermediate Algebra: Section 6.7: Factoring - Solve by Factoring"
Read this section. Here we emphasize how we can solve problems by factoring. Focus on the rule - "if ab = 0, then a = 0 or b = 0 (or both)" - and how factoring makes this rule so important.
Click https://s3.amazonaws.com/saylordotorg-resources/wwwresources/site/wp-content/uploads/2011/12/SAYLOR-MA001-TEXT.pdf link to open resource.