1. Lesson 4

1.8. Explore 4

Mathematics 20-1 Module 6

Module 6: Rational Expressions

 

Factoring to Find the LCD

 

You have now learned the basics of solving rational equations. You can apply the principles you have learned to other rational equations. In order to identify the lowest common denominator more easily, try factoring the denominators. Keep this in mind as you complete Try This 3.

 

Try This 3

 

Study the following rational equation:

 

 

 

How would you solve this equation? The approach you learned previously can be applied here. Follow the steps in the table to determine the solution.

 

 
Step Your Work
Step 1: Determine the non-permissible values.  
Step 2: Determine the LCD.  

Step 3: Multiply by the LCD.

 

Step 4: Solve for x.

 

 

course folder Save your work in your course folder.

 

Share 2

 

With a classmate discuss the following questions.

  1. Compare and contrast the work required to solve to the work that was required to solve

  2. In the last step, you should have obtained two possible roots. However, did you notice that one of the roots is also a non-permissible value? What does this imply?

course folder Save your work in your course folder. You will refer to your responses later in the lesson.


What method of solving a quadratic equation is appropriate here?
What is the resulting equation when the LCD is applied to each term of the expression, including the term on the right side of the equation?
What binomial factors are required in the LCD?
How does factoring help you to identify the non-permissible values?