1. Lesson 1

1.10. Explore 9

Mathematics 30-1 Module 8

Module 8: Permutations, Combinations, and the Binomial Theorem

 

As you may have noticed in Try This 5, writing out all the factors can take a long time. Here is another way you could simplify

 

Expanding the numerator and denominator gives you

 

 

 

As you can see, the expression in the brackets is the same as 9!. Therefore, you can write as

 

Dividing the numerator and denominator by the common factor of 9! leaves 12 x 11 x 10, or 1320.

 

Self-Check 5
  1. Simplify.
    1. Answer
    2. Answer

glossary

Add factorial notation to your copy of Glossary Terms.



formula sheet

Add the following formulas or ideas to your copy of Formula Sheet:

  • fundamental counting principle
  • tree diagram
  • factorial notation