Tyler Wallace's "Beginning and Intermediate Algebra: Section 7.3: Rational Expressions - Least Common Denominators"

Read this section. One of the skills students have most difficulty with is adding fractions. You can make this much easier by understanding least common denominators.

Click https://s3.amazonaws.com/saylordotorg-resources/wwwresources/site/wp-content/uploads/2011/12/SAYLOR-MA001-TEXT.pdf link to open resource.