Adding and Subtracting Rationals

These are the notes I wrote for adding and subtracting rational expressions last year in Algebra 2.

On the first page, I wanted to make the connection between rational expressions and fractions explicit, so I started with a reminder of how to add and subtract fractions. The two examples were chosen deliberately; the first only required changing the denominator on one fraction, while the other required changing both denominators. Students need to deal with both types of problems with rational expressions.

The next part introduced two simple problems, with only one denominator being changed between them. They are both problems that require simplifying, as I wanted to emphasize the need to do this from the start. (Students had already seen how to simplify rational expressions and stating excluded values.)

The next page was about finding the lowest common multiple. I had students use a strategy which emphasizes the definition of the LCM, having them multiply by factors so that the two expressions are the same.

And finally, a couple of examples putting all of this together.

Downloads are available here.


Algebra 2 Practice Book ver 0.1.1

Here’s the latest version of my Algebra 2 Practice Book. I’ve started Chapter 7 now, with questions for the following sections:

7.1 Reciprocal Functions. I prefer this title over “Inverse Variation”, as that’s too easy to confuse with inverse functions.

7.4 Simplifying Rational Expressions. This also includes simplifying products and quotients of rational expressions

Downloads are available here:

Mr. Carter’s Algebra 2 Practice Book
Version 0.1.1 (January 30, 2018)

Chapter 5: Polynomials Part A

Chapter 6: Polynomials Part B

Chapter 7: Rational Functions and Expressions

A reminder that these are early drafts of what is very much a work in progress. All content is subject to change.

Copyright Shaun Carter © 2018. Teachers may reproduce these documents for use in their own classroom only.