Khan Academy: Algebra: Adding and Subtracting Rational Expressions Example 3

This worksheet contains a good selection of problems of adding and subtracting rational expressions. There are eight problems. None of the problems have common denominators.  A few are mixed expressions and some require factoring....

There's a fine line between a numerator and a denominator! Learners find common denominators in order to add and subtract rational expressions. Examples include addition, subtraction, and complex fractions.

Finishing up his short series on rational expressions, Sal reviews the concept with another example. Those who have a hard time with rational expressions will appreciate the clarity with which Sal explains his process and methodology.

Video shows example of adding and subtracting rational expressions. Includes discussion of using the least common multiple of the denominators for a common denominator. [2:56]

Video showing how to add and subtract rational expressions by finding a common denominator and then simplifying the result. Also includes finding the domain of the result. [8:15]

Video shows examples of multiplying and dividing rational expressions. Includes adding restrictions to the simplified answer. [9:19]

Video lesson involving dividing rational expressions and simplifying the result by factoring out the greatest common factor. Includes stating the domain of the expression. [4:10]

Video lesson involving multiplying two rational expressions, simplifying the result and then stating the domain of the expression. [3:38]

Video lesson on multiplying rational expressions and simplifying the result by factoring the difference of squares. Includes stating the domain of the expression. [4:52]

Sal explains what it means to simplify a rational expression and why we would want to do that. Just don't forget the excluded values! [15:22]