Objectives:

Standard 15.0• I will find the LCM (Least Common Multiple) of

the given denominators• I will simplify the rational expressions by using

the LCM of the given denominators

Review 1Find the LCM of 24 and 36.Step 1: Express 24 and 36 in its factors using factor tree.

LCM

Important: When finding LCM, take the highest exponent of the same factor.

Review 2Find the LCM of 24 and 27.Step 1: Express 24 and 36 in its factors using factor tree.

LCM

Important: When finding LCM, multiply the factor even it is not a common factor for both given numbers.

Finding the Least Common MultipleExample 1Find the LCM of the following pair of polynomials. and Step 1: Align the polynomials vertically.

LCM

Finding the Least Common MultipleExample 2Find the LCM of the following pair of polynomials. and Step 1: Factorize each polynomial.

LCM

Finding the Least Common MultipleExample 3Find the LCM of the following pair of polynomials. , and Step 1: Factorize each polynomial.

LCM

Practice from Textbook

• Textbook A44 Q.53-60

Objective

Standard 15.0• I will use the LCM of the denominators to add

and subtract rational expressions

Using the LCM to Add Rational ExpressionsExample 1 where Step 1: Factorize the denominatorStep 2: Find the LCM of the two denominatorsStep 3: Multiply factored polynomials to each rational expressions to make the common denominator

Using the LCM to Subtract Rational Expressions

Example 2 where Step 1: Factorize the denominatorStep 2: Find the LCM of the two denominatorsStep 3: Multiply LCM to each rational expressions to make the common denominator

Practice from Textbook

• Textbook A44 Q.61-68• Once you are done, you can continue to work

on Textbook A44 Q.69-72