Lesson 3

You have discovered that adding or subtracting rational expressions is relatively straightforward when the expressions have common denominators. What do you do when the denominators are different?

 

Before moving to Try This 4, make sure you understand how to determine the lowest common multiple of two numbers. If you feel you need a review of the two methods, watch Making Equivalent Fractions: Factored Form and Making Equivalent Fractions: GCF × LCM to see these methods in action.

 

 

Try This 4

 

In the Are You Ready? section, you added and subtracted rational numbers that had different denominators. Still, the question remains: can you verbalize the steps involved in the calculation?

 

Following are the worked-out steps for Use the words numerator, denominator, and rational numbers to describe the steps being followed.

 

Question/Steps	Explanation of Step
12 = 2 × 2 × 3 20 = 2 × 2 × 5

 

Save your responses in your course folder.

 

Share 3

1. Switch explanations with a partner. Use the steps provided by your partner to solve the question
2. Do any of the steps need rewording for full understanding? 

If required, save a record of your discussion in your course folder.